The RS line of cars was Audi's foray into supercar performance, though it only came as an Avant wagon in the late 1990s. 2007 marks the return of the RS4 as a sport racing sedan. Based on the A4 and S4, but with fewer standard features in an effort to reduce weight, the 2007 RS4 is the first RS without a turbo engine. Instead, it features a direct fuel injected 4.2-liter, 420-hp DOHC V8 with a 6-speed manual transmission. It's been clocked at 0-60 in 4.7 seconds. Torque distribution in the revamped quattro all-wheel drive is 40/60 front/rear, with peak torque at 7600 rpm. It features more aluminum body parts and a stiffer suspension than the sporty S4 and comes standard with dynamic ride control for a more balanced handling. The 2007 RS4 is distinguishable on the outside with flared fenders, borderline ostentatious oval exhaust pipes, wide 19-inch wheels, and an integrated rear spoiler. Another way that Audi kept down weight in this car is by not offering a spare tire. For good or bad, a repair kit is included instead. The 2007 RS4 hasn't sacrificed that many luxury conveniences in the name of weight, however. It is still loaded with personal luxury and comes standard with 10-way power-adjustable, heated leather Recaro sport seats, a sunroof, parking assist, remote locks, cruise control, and power tilt steering wheel. Options add on Bluetooth, automatic climate control, a navigation system, and heated rear seats. Great revving performance and exhaust noise accompany the smooth and awesome V8 power of the 2007 Audi RS4, according to owners and experts. This is a true sports car, but with the added benefit of Audi's quattro technology and refined engineering. It is also not as flashy as some supercars, for those who want more understated looks (to slip by undetected on the highway). The price tag and low fuel economy are the main complaints of owners, but nothing suprising for a high performance car.