Starting price: $66,910
Power: 4.2-liter, 420-hp V-8
2nd place : Mercedes-Benz C63 AMG
3rd place: BMW 335xi
Ask an automotive engineer -- off the record -- to state a benchmark, and chances are he'll pick an Audi. And then there's a high-water mark like the RS 4, which is innovation-rich, ridiculously quick, and competent at everything from daily driving to track-tough floggings.
Touches like bi-xenon high intensity discharge headlights, an aggressive front diffuser, and a svelte spoiler on the rear deck are icing on a rocket.
NEXT: Mid-size sedan: Jaguar XF Supercharged
Last updated July 01 2008: 11:45 AM ET