Engine wise, it depends on what year you're interested in. 2006 models all have the same 3.5L 300hp powerplant. In 2005 it was standard in the Anniversary model and on the Track Edition, while the remaining 04's and all 03's had the 3.5L 287hp engine.

It all depends on what you're interested in. I just didn't see paying all that extra loot for traction control I wouldn't use, big Brembo brakes, etc.