It cant be all that different. Other than road noise, the car should behave exactly the same. The frame of the SRT-10 Conv. is SO stiff, that any stiffer is really a moot move. The Coupe is heavier by about 80 lbs. Coefficient of drag is the same if I recall, though the coupe makes slightly more rear downforce. other than that... its apples to.......apples?