The Good: The 2006 Honda Civic Si packs serious drivetrain technology and excellent front-drive handling into a less-than-$20,000 package. A superior navigation system and satellite radio are also available. The Bad: The electronic throttle can be tough to modulate. Bluetooth integration is not available in the 2006 Honda Civic Si. The Bottom Line: The 2006 Honda Civic Si is a real performance bargain that also offers good mileage and emissions ratings. The quality of the electronics is equivalent to that found in much pricier vehicles. Simple standard features fit the car's mission well, signaling the Si's return to form. Our first short drive in the 2006 Honda Civic Si left us with a very positive impression, and the car's recent week at CNET headquarters did nothing to change this. Praise for the rev-happy engine and slick transmission was universal, and everyone who drove the Si came away smiling.The previous-generation Honda Civic Si was largely a disappointment to the Si faithful, without the zip and the agility that had defined the earlier versions. This eighth iteration is heavier and larger than the car it replaces but is also substantially quicker, making it both more comfortable and inspiring behind the wheel.Also satisfying longtime fans is the return to a true two-door coupe layout, with decidedly aggressive styling further separating the new car from the unloved hatchback it replaces. Rated trunk volume is down slightly from the hatchback's capacity, but the 2006 Honda Civic Si's rear seats and trunk both offer usable space, given the car's overall dimensions.Interior tech features are well designed, with satellite navigation differentiating the two available trim levels. Our test car wasn't outfitted with the voice-recognition navigation system, which also includes an in-dash PCMCIA card reader and an XM radio tuner, but the auxiliary audio input and the MP3\/WMA playback capability are fine standard features. We tested the navigation unit in our earlier review of the 2006 Honda Civic Hybrid and concluded that it's a first-rate, worthwhile option.At a list price of $20,540, including a $550 destination and handling charge, the 2006 Honda Civic Si offers overall performance that none of its direct competitors can better and rounds out the value equation with good build quality, up-to-date tech features, and fuel economy that will save dollars over the course of ownership.The interior of the 2006 Honda Civic Si sets itself apart from its less-sporty Civic brethren with bolstered sport seats, a thick-rimmed three-spoke steering wheel, and textured aluminum pedals. The short-throw shifter for the six-speed transmission is also aluminum, with a leather grip.The Civic coupe's steeply raked windshield makes plenty of room for the two-tiered dashboard layout, with a large analog tachometer dominating the lower portion and a digital speedometer flanked by temperature and fuel gauges in the upper hump. The low, broad dash translates to great forward visibility, and the stubby rear overhang offsets the rising waistline and rear wing to make the view out the back nice too. A standard power moonroof adds to the airy feeling in the cockpit.Although the display is small, this stereo produces excellent sound.The 2006 Honda Civic Si's standard seven-speaker, 350-watt audio system has no trouble filling the car's interior. Bass response is strong from the 8-inch subwoofer, and overall, the sound remains clean within reasonable volume levels. While the navigation system with card reader ($1,750) would be the obvious technophile choice, the simple, large knobs and buttons of the non-navi layout win points for ease of use. That said, the single-line LED readout is inadequate for song info coming from an MP3 player or burned CDs, and had the XM radio tuner been present, we would have been really frustrated. On the plus side, the readout can display a customized message on powering up, cell phone style. Steering-wheel controls are available for volume, audio channel, and the usual cruise-control functions; the nav option adds further controls to the wheel.The navigation option, as tested in other Hondas, comes with a truly usable voice-command feature. The nav system gives fast and accurate route calculation and has a large database of businesses, facilitating weekend errand running. The voice-command interface is easy to learn and extends to control the temperature and the stereo.An auxiliary input and a power point at the bottom of the stack are perfect for plugging in an MP3 player.No provision for Bluetooth cell phone integration is available, although the center console of the 2006 Honda Civic Si houses a second 12V outlet; you could, for example, charge a phone while using the dash outlet for another gadget. The cup holders between the shifter and the adjustable center armrest accept different-size drinks well.The rear seat backs split and fold 60\/40, with releases from both the interior and the trunk. With the seat backs up and the front seats in the midrange of their adjustments, there is a fair amount of legroom in back. There are seat belts for three rear passengers, but they would make for a very tight fit.The 2006 Honda Civic Si packs an impressive amount of technology into the drivetrain of what is essentially an economy car. First and foremost is the engine, a small-displacement gem that spins its way to 8,000rpm with a howl befitting the distant cousin of a Formula One contender.From a 2.0-liter, all-aluminum, in-line four-cylinder configuration, Honda squeezes 197 horsepower and 132 pound-feet of torque using a high-volume intake manifold and iVTEC, which encompasses its full arsenal of computer-controlled variable-valve timing and lift-control programs. These systems maximize efficiency and low-end torque, giving sparkling performance while also maintaining EPA-rated mileage figures of 23mpg in the city and 32mpg on the highway, as well as a LEV-2 CARB emissions rating.The sport seats are covered by grippy fabric, and the six-speed shifter is a source of joy.Falling (perhaps deliberately) just short of the revered 100-horsepower\/liter figure achieved by its pricier stablemate, the 2006 Acura RSX Type-S, the 2006 Honda Civic Si is still the more engaging drive of the two. This may have been partially due to the more aggressive rubber found on our Si's 17-inch alloy wheels. We enjoyed our week last summer with the Type-S, but the new Si will certainly cannibalize its sales from below.What sets the handling of the two apart is the 2006 Honda Civic Si's limited-slip differential (LSD), which gives it a clear advantage in lateral acceleration. The LSD acts to send torque to the front wheel with the most grip, allowing the outside loaded wheel to pull the car through in a turn and avoiding wasteful spinning of the inside wheel, which is traveling a shorter distance. Especially in a powerful front-wheel-drive car, this makes a big difference in cornering feel, and with it, the Civic Si has the edge on both the Type-S and the new Volkswagen GTI. Torque steer from rest in a straight line is evident but not intrusive.This engine is happiest around 6,000rpm--plenty of room before its 8,000rpm redline.The six-speed manual transmission has well-spaced ratios, and the throws are short, inspiring frequent use. But as we noted after our first drive of the Civic Si a couple of months back, the notchiness we loved in the RSX Type-S gearbox is somehow missing in the Si. It's not enough to detract from the driving experience, but we would enjoy a slightly more direct feel to the shifter.Another mild annoyance that we didn't notice on the, ahem, aggressive short intro drive was the drive-by-wire throttle's lack of response when getting off the pedal. Rather than dropping as the pedal is released, the revs hold level for a solid second before beginning to fall. In our week's experience, we never quite mastered the rhythm of mellow midrev upshifts. The short throws mean you're into the next gear before the engine falls to where it would have been without the delay; it takes some getting used to. One of our testers also complained of high-pitched valve-train whine becoming tiresome during sustained cruising, but this wasn't noticed by everyone.The 2006 Honda Civic Si offers the usual standard passive safety features: dual-stage, dual-threshold front air bags; front side air bags with an occupant-position sensor; and side curtain air bags. ABS is standard on the Si's four disc brakes; rear drums are standard on the base-model Civics. The Si gets larger ventilated front discs than the next cheapest EX, at 11.8 inches to 10.3. Electronic brake-force distribution is standard on all Civics.Front and rear crumple zones help the 2006 Honda Civic Si achieve five-star NHTSA frontal crash ratings. Side crash ratings are not yet available, but side-impact door beams come standard on Civics. Daytime running lights are also standard.Honda's new-vehicle warranty is good for three years\/36,000 miles, with rust-perforation protection extending to five years and unlimited miles.