2006 Cadillac STS front

Cadillac built its second legit sedan using the same architecture of the first (the CTS). This enlightened version of what used to be the Seville now sends its 255 or 320 horsepower (V6, V8) through the back end instead of the front, and unlike its competitors, Cadillac wisely paired the optional all-wheel-drive with both engines, not just the V6. The new STS-V brings the most compelling powertrain yet: a 4.4-liter V8 that's been supercharged to 469 horsepower, which happens to be the exact power output of Mercedes' E55. Coincidence?