aerodydamics

ok what is better for aerodynamics a 2004 mustang cobra or a corvette c5? what body kits are avalible to improve aerodynamics

Both manufacturers should have coeffeciants of drag. Dealerships will most likely have the info.
I have heard bomex does wind tunnel testing. I don't know if they make kits for those cars. Most kit manufacturers put very little thought into aerodynamics.

based on just a general SWAG (Scientific Wild Ass Guess) and from looking at the shapes in profile I would venture to say that the 'Vette will be the more slippery shape. However, without analysis in a wind tunnel it is impossible to know which shape generates less lift.

I have no idea about the body kits since I have never used one, but I'd have to agree with ^ that most commercially available body kits are for looks only.