Full Description: The 2010 Audi A4 sedan is a slick-looking and smooth-driving sport sedan, and its Avant wagon variant is possibly slicker still. Just make sure you're onboard with the mandatory four-cylinder engine.At first glance, it may appear as though the 2010 Audi A4 lineup has been eviscerated. The convertible is gone, and so is the V6 -- what's next, cloth upholstery and crank windows? In actuality, though, there are perfectly good explanations for both developments. The good folks at Audi haven't lost their minds, and the 2010 A4 remains an eminently desirable sport sedan/wagon with arguably the nicest interior in this segment.Now for the explanations. Let's start with the convertible. Last year's A4 drop top was an outdated design based on the previous-generation A4, so its torch has been passed to the foxy new A5 Cabriolet. As for the pricey V6, it couldn't even outperform the base turbocharged four, so Audi will henceforth send its new supercharged S4 (reviewed separately) into battle against upper-crust contenders like the BMW 335i, while the four-cylinder A4 2.0T will continue to lock horns with entry-level sport/luxury cars like the BMW 328i and Mercedes-Benz C300. See? It all makes sense. All is well in Ingolstadt.One thing that hasn't changed about the A4 is its precise and balanced handling, which combines with its slick styling and upscale cabin to provide an undeniably premium driving experience. Indeed, the only pressing question about the 2010 A4 is whether that four-cylinder engine is up to the task given that most of its rivals offer smooth six-cylinder power. To be fair, the A4's turbocharged 2.0-liter four puts up competitive acceleration numbers despite its cylinder deficit. Yet the only luxury cars of this sort with four-cylinder power are ones on the fringe like the front-wheel-drive Acura TSX.4-Cyl Turbo 2.0 Liter,Auto 6-Spd OD Tiptronic,AWD,Hill Hold Assist Control,Traction Control,Electronic Stability Control,ABS (4-Wheel),Anti-Theft System,Keyless Entry,Air Conditioning,Power Windows,Power Door Locks,Cruise Control,Power Steering,Tilt & Telescoping Wheel,AM/FM Stereo,CD/MP3 (Single Disc),Sirius Satellite,Bluetooth Wireless,Dual Air Bags,Side Air Bags,F&R Head Curtain Air Bags,Heated Seats,Dual Power Seats,Dual Moon Roofs,Xenon Headlamps,Daytime Running Lights,Fog Lights,Roof Rack,Alloy Wheels,