The Good: The 2008 Jaguar XKR Convertible combines all the beautiful sheet metal of the XK with a punchy performance upgrade for a tech- and comfort-laden ride with feline handling. The Bad: Despite shelling out more than $100K, XKR Convertible owners have no way to listen to their iPods on the road. Rear three-quarter visibility with the soft top up is extremely limited. The Bottom Line: With a six-figure price tag, you'd expect the 2008 Jaguar XKR Convertible to have it all--and it nearly does. Its refined cabin, elegant and advanced technology, supercharged V-8, consummate handling, and traffic-stopping looks make it an all-round winner. Photo gallery:2008 Jaguar XKR ConvertibleWhen we reviewed the naturally aspirated 2007 Jaguar XK last year, we were smitten by its gorgeous looks, refined power, and balletic handling. A week after we (reluctantly) gave our test car back, Coventry unveiled the XKR and we fell in love all over again. It's difficult to describe the difference between the XK and the XKR: to continue the ballet theme, if driving the XK was like sipping champagne with a ballerina, then getting behind the wheel of the XKR is like doing shots of vodka with Vaslav Nijinsky. With a 420-horsepower Eaton-supercharged 4.2-liter V-8, the XKR is one of the most powerful cars to ever roll out of a Jaguar factory, and with the family resemblance to the beautiful XK still intact (albeit with a few "R"-inspired blemishes), it is also one of the most attractive. Like the XK, the XKR manages to combine Jaguar's signature luxury appointments with some impressive technology, including an intuitive navigation system and optional adaptive cruise control. Test the tech: Remote control cruise control We've seen a number of high-end cars with adaptive--or intelligent--cruise control (ACC), a system that relies on forward-looking radars to detect the distance of the host car to the car in front, and then uses braking and throttle inputs to automatically keep that distance constant. While we found Lexus' system to be laggardly, taking a long time to get the car up to speed, we were more impressed with the versions from Acura and Mercedes-Benz. The Jaguar system compares well against the luxury competition in both its ease of use and effectiveness on the highway. To set the ACC in the Jaguar XKR Convertible, drivers use a couple of rotary dials mounted on the right-hand side of the steering wheel. One of these controllers sets the car's maximum cruising speed, the other is used to select one of three preset distances from the car in front. The XKR's adaptive cruise control is set using steering-wheel-mounted rotary controls.With the ACC set, the car accelerates until it reaches the designated speed, which it maintains until the driver steps on the brake or the accelerator, or--and here is the magic of ACC--another car is detected within the preset proximity to the Jaguar's front bumper. When this happens, the XKR automatically slows itself down to the speed of the car ahead. Usually, this process involves a smooth deceleration, and we found the XKR's intervention to provide a good balance between comfort and a reassurance that the system had things under control. When cars from adjacent lanes cut in front of us, the XKR applied the brakes more sharply. On one such occasion, the driver information display panel flashed a "Driver Intervene" message, requiring us to apply the brakes ourselves. Curiously, following this warning, the ACC system would not function again until we shut down and restarted the car. When the ACC detects that the obstacle ahead has accelerated or has left the lane ahead, the XKR gets itself back up to speed quickly. The sensation is one of being pulled up to speed, almost as though the car is being towed along. Over the course of hundreds of miles of driving in our week with the XKR, we developed confidence in the ACC system and found it to be a useful aid in the hassle-ridden stop-and-go of Northern California's freeways. In the cabin Jaguar succeeds in combining luxury and comfort with well-integrated technology in the cabin of the 2008 XKR Convertible. A few cosmetic interior signs differentiate the XKR from its naturally aspirated sibling, including "R"-embossed headrests, and "R" logos on the top of the shifter and the bottom of steering wheel. A carbon-fiber effect interior trim is also available on the XKR in place of the more traditional walnut paneling, and those looking hard will also notice the polished pedals in the 2008 version of the supercharged model. On the outside, the XKR sacrifices some of the elegance of the XK in favor of a few performance-inspired design clich\u00c3\u00a9s, including hood vents and a few square feet of chicken wire on the grille. According to popular legend, the XK series was originally designed as a convertible with the coupe as an afterthought. With the soft top down (Jaguar says it decided against a hard top for aesthetic reasons), this really shows, as the XKR Convertible's bold beltline merges with the sculpted tonneau cover to produce a car with dashing lines. The decision to eschew a folding hard top also means that the convertible maintains the same 2+2 seating layout as the XK coupe (rear seats are still useless to anyone outside a baby seat), and--more importantly--that the convertible weighs in at just 88 pounds more than the coupe. The fluent lines of the XKR convertible are most visible with the top down. A roof-mounted button brings the XKR Convertible's top up or down in around 18 seconds. In our time with the car, we were blessed with some fine November California weather, which meant that we could drive the Convertible as it was meant to be driven: topless. The flowing design of the car translates to great aerodynamics, and even at freeway speeds, the XKR Convertible displayed very little wind noise. Adding to our inclination to favor a top-down drive is the fact that, with the top up, rear visibility is greatly impeded by the roof. Like that of the XK we tested last year, the cabin of our XKR Convertible review car featured a forest of rich dark-wood trim for the dash, center console, and door panels, and attractive leather finishing on the cowl and the front seats. The latter are upgraded with extra lateral support in the XKR, to keep drivers in their seats as they dive into or power out of corners. For more sybaritic-minded drivers, the Luxury Package equips the XKR's heated front seats with 16-way power adjustment. In a particularly tasteful design cue, the roof of the XKR is trimmed with a suede-like material called Alston. As one might expect on a car with a base sticker price of $92,035, the XKR Convertible comes with a GPS navigation system as standard. This takes the form of an in-dash touch-screen LCD, which displays bright, colorful maps and intuitive programming menus, and a useful matte finish, which minimizes glare with the top down. Destination entry is straightforward, with drivers able to plug in an address or a point of interest, or make a selection directly from the map. When under route guidance, the XKR gives clear and accurate turn-by-turn voice directions, and while it does not have text-to-speech capability for reading out the names of individual roads, it displays the name of the current or forthcoming road on the screen. The XKR's as-standard navigation system provides colorful and well-rendered maps.The in-dash display also serves as the primary interface for all the XKR's entertainment and communications features. For music playback, the system supports regular CDs and MP3 and WMA-encoded discs, providing a useful interface for navigating folders and tracks for the latter. Sirius Satellite radio is available as an option, but there was no evidence of an auxiliary-input jack for hooking up our iPod, nor does Jaguar provide an option for an intelligent iPod connector. On a more tech-friendly note, the 2008 XKR Convertible does come with Bluetooth hands-free calling as standard. With a phone paired, drivers are presented with an onscreen keypad to dial outgoing calls, which is accessible even when the car is moving along. Incoming calls can be answered and all calls can be ended using the voice button on the left of the steering wheel, which also doubles as a useful one-touch means of muting the audio system. Bluetooth hands-free calling comes as standard on the XKR.The other notable tech feature of the XKR's cabin is its secondary LCD display located between the speedometer and the tach in the instrument panel. This rectangular, full-color display gives helpful--and very visible--information on the car's systems, such as open doors and engine notices, as well as trip information and figures on average mileage. Under the hood A few logos, some boy-racer cosmetics, and some minor luxury features may be the only things to differentiate the XKR from its XK sibling while the car is standing still, but on the open road, the difference is startling. With the addition of a supercharger, the XK's all-aluminum AJ V-8 gets an upgrade from 300 to 420 horsepower. This is enough to catapult the XKR to 60 mph in 5 seconds, and sufficient to justify the car's specially bolstered seats during cornering. The XKR's hood vents suggest performance, the driving experience confirms it.With the top down, the most striking thing about driving the XKR with gusto is the sound of the engine, which, to borrow a phrase from Jeremy Clarkson's scriptwriter, sounds like the god of thunder gargling with nails. The only real way to maximize the potential of the XKR's sequential shift transmission is to use the steering-wheel-mounted paddle shifters. These give drivers the advantage of being able to hold the gears longer as well as a useful throttle blip during each gear change. In fast acceleration, this extra squirt of juice during upshifts leads to a satisfyingly linear acceleration, while in downshifts it makes torque instantly accessible. A byproduct of the throttle-blip in city driving is that the XKR Convertible announces itself with a throaty snarl when pulling up to a stoplight, grabbing the attention of those few passersby who had failed to notice it from its stunning looks alone. For those who don't want to drive the XKR like a sports car (who are you?), the gearbox can be left to its own devices in either regular drive or sport mode. Goodbye J-gate, hello reverse L gate.To make the most of our early Christmas present, we took the XKR Convertible through its paces on some of the straightest and most deserted roads in central California, with our particular favorite being I-198 between 101 and I-5. There, amid the tundra and the craggy mountains, we managed to do justice to the Big Cat's whirlwind acceleration and handling prowess. While the performance stats of the XKR Convertible are undeniably impressive, the car's power arrives without the brute force of the Ford Shelby GT-500. Gunning the throttle from standing results in a whine from the supercharger as the XKR's hood rises up and the car rears back on its 20-inch wheels, but the forward momentum is smooth and the speedometer can arrive in extra-legal territory with worrying ease. Our favorite aspect of driving the XK was its consummate handling and balance, and the XKR Convertible delivers an equally razor-sharp ride. Front and rear springs and dampers are enhanced on the XKR to the tune of 38 percent and 24 percent, respectively. Added to the model's 52\/48 weight distribution, Jaguar's eCATS two-stage damping system, and the XKR's monocoque body structure leads to a delightfully surefooted ride. Apart from our canyon carving, we put in a good deal of freeway time in the XKR Convertible, covering more than 400 miles in our time with the car. Over this distance, we observed an average gas mileage of 18.4 mpg. Nothing to boast about, but much better than our observed average in city-only driving, which came in at a dismal 12 mpg. Outside of the United States, the XKR Convertible is equipped with Jaguar's innovative Pedestrian Deployable Bonnet System (PDBS), which fires a pyrotechnic charge underneath the hood in the event of a frontal impact to provide a cushion between the hood itself and the engine underneath it. The system takes less than one-tenth of a second to deploy and is aimed at reducing the impact of a collision on pedestrians. Bizarrely, the system is not available in the United States, according to Ford, because of "U.S. safety regulations." In sum Our 2008 Jaguar XKR Convertible came with a base price of $92,035. To that we added $5,000 for 20-inch Senta wheels, the $2,500 Luxury Package (soft-grain leather seats, soft-grain leather-wrapped instrument panel, doors, and center console, power fold feature on exterior mirrors, 16-way power-adjustable seats, heated leather-trimmed steering wheel, and leather-trimmed gearshift knob), the $2,450 Advanced Technology Package (Adaptive Cruise Control and Front Park Control), and $1,875 for the premium sound system. All told, our Big Cat prowled off the lot for an eye-watering $104,275. Well-heeled prospective customers might also want to consider the Mercedes-Benz CL550 (for a bit more cabin tech), or the BMW M6 (for a bit more performance hooliganism). For a combination of comfort, luxury, performance, and styling, however, the XKR Convertible is about as good as it gets.