The Good: Excellent LCD and Birdsview navigation; solid Bluetooth hands-free system; dedicated rear-seat entertainment system; clever backup camera. The Bad: Rear-seat DVD monitor clobbers driver's rear view; no live traffic data in navigation system; proprietary knob and screen interface takes time to master. The Bottom Line: The Infiniti M45 takes off with sporty performance but finishes a close second to the Acura RL in cutting-edge tech. 2006 Infiniti M45Just when you thought the 2005 Acura RL ruled the high-tech road among sporty four-door sedans, along comes Infiniti's M45 to shake things up with its arsenal of tech toys and a lot more power under the hood than the Acura flagship. We tested a moderately equipped M45, powered by a 4.5-liter V-8 delivering 335 horsepower through a five-speed shiftable automatic transmission. We also had it outfitted with the Journey package (eight-speaker Bose stereo, backup camera, automatically leveled and steered headlights, and climate-controlled seats) and the optional mobile entertainment system, comprising a rear-seat DVD\/audio system with a remote control, wireless headphones, and a DVD navigation option. It all comes to a package worth about $54,000.\r\n\r\nHop into the driver's seat, and your eyes will gravitate toward the dash-mounted, seven-inch LCD. The 2006 Infiniti M45's display quality is smooth and nicely saturated. The onscreen user interface struck us as fairly logical. We didn't have to work as hard to get the menu system as we did with say the Acura RL. And it doesn't hurt that bright-sun visibility of the M45's screen is better than the , for example. Still, like most cars that have a first-generation LCD screen interface driven by a multifunction knob, there's a learning curve. After three days with this car, we still had to poke around the menu system to find controls for navigation, climate settings, and audio.\r\n\r\nOf course, one of the main uses for the LCD is the M45's navigation system. The 3D bird's-eye-view map it provides is a great contextual tool. This perspective lets you look down on the roads and see what lies ahead, making geographical relationships clear and alleviating some of the stress of travel. Less delightful are the voice prompts that accompany route guidance. Two slightly different voices speak, one for directional instructions ("turn right") and the other for street names ("Columbus Avenue"). The result is a sort of navigational Martin & Lewis routine, only not funny. The voice that handles street names is decidedly less intelligible than the one that gives directions. We would have preferred if street names were displayed on the dash as text only. If voice prompts are important to you as a guidance aid, then definitely give the M45's navigation system a listen during the test-drive. Also, Infiniti doesn't yet offer NavTraffic, as do Acura and Cadillac, so there's no real-time traffic data.\r\n\r\nThe M45's voice-recognition system can operate many of the car's cabin functions, including climate, audio, navigation, and communication systems. Perhaps most enjoyable was using it to enter new navigation addresses while on the road, a handy feature that will keep you from having to pull over and stop every time you want to enter or amend a destination--a complaint we had with the . The voice recognition was aided by the fact that this is a high-end car with a relatively low interior noise level.\r\n\r\nWhen you put the car in reverse, the backup camera, which is located above the rear license plate, takes over the main LCD. Instead of simply showing you a standard rear view, the M45's system overlays color-keyed marks on the camera's wide-angle image that indicates where the curb is and helps you gauge your distance from the object. There's also a pair of yellow parallax lines that predict where the car will go as you steer backward. And as with just about all backup camera systems we've tested, the M45's adapts well to bright daylight and dim night conditions--chalk one up to the amazing development work done by the digital camera industry over the last few years!\r\n\r\nWe were impressed by the M45's Bluetooth hands-free system. It gave us no hassles when paired to our Treo 650. Incoming and outgoing calls were seamlessly handed to the hands-free system without any clipped syllables. Callers on the other end reported that the M45's cabin mic quality was about average, but we definitely sounded like we were on a speakerphone. As with all cars incorporating a Bluetooth hands-free system, we recommend that you talk to the service department at the dealership to have them verify compatibility with your particular phone and perhaps even its firmware version.\r\n\r\nWhile calls sounded good, we couldn't say the same for the stereo. Considering the Infiniti M45's $54,000 price tag, we expected more from the Bose audio system included with the Journey package, but it's basic by today's high-end standards: eight speakers driven by 230 watts of power; a six-CD MP3-capable changer that outputs stereo only; and no surround sound. For a richer audio experience, check out the optional $4,250 Premium package that adds 5.1 studio surround-sound audio with DVD-Audio playback and several safety features (see below). We appreciated that Infiniti offers buyers both Sirius and XM radio packages and that station preset lineups can include a mix of AM, FM, and satellite stations side by side.\r\n\r\nRear-seat passengers in our test M45 were treated to a motorized, drop-down eight-inch wide-screen LCD monitor in the headliner. It's a real crowd-pleaser, as your passengers can watch a DVD, the car's navigation screen, or any video portable on this system. You can listen to audio via the included wireless headphones, which sound tinny compared to the car's speakers. And of course, audio portables can be connected via a set of rear-facing aux-in jacks mounted in the armrest console. A big drawback to the rear-seat entertainment system, though, is that its monitor decimates the driver's view to the rear. We would prefer to see Infiniti install the LCD monitors in the back of each front headrest.\r\n\r\nFor safety, the Infiniti M45 features dual-stage front, side, and curtain air bags, and as we mentioned before, the Premium package adds a couple of safety options, including Intelligent Cruise Control, which uses an array of lasers to measure the distance between you and the car ahead while in cruise control, then automatically adjusts your set speed to maintain distance. There's also Infiniti's unique lane-departure warning system, which tracks the distance between your car and the divider lines. The M45's warranty covers the car bumper to bumper for four years\/60,000 miles and the power train for six years\/70,000 miles, which is slightly better than average for cars in this class.