2006 Cadillac STS

Cadillac has made it clear that it intends to give the V-Series treatment to more than just the CTS, so it wasn't much of a surprise when heavily modified prototypes of the STS were photographed making the rounds at Germany's Nurburgring test track. Power is expected to come from a supercharged version of Cadillac's 4.6-liter Northstar V8 putting the STS-V in the 400-500-horsepower range. And don't be surprised if it shows up with a six-speed manual transmission either as Cadillac fully intends for this car to be a true competitor to BMW's M5 super sedan.