Tino wrote:they add weight? you sure about that? aerodynamics too?
Yep, pretty sure. You are only adding to the body of the car, and thus, you are adding weight. Weight is bad, usually, unless you drag race often and have so much power that your car starts coming off the ground. As far as aerodynamics, unless you have go extremely fast very often, you aren't going to help yourself by changing the aerodynamics, in fact, many kits may actually hurt the aerodynamics, depending on what style they are.