the car has to be in original. my dart has a hotchkiss front suspension, the best you can get i guess. it's not permitted. front and rear sway bars, forbidden, every exhaust system which is not similar to the original one, forbidden, tinted windows in the front row, forbidden, different rims, forbidden...
well, you can get a permission for everything here, but then you have to pass an individual 'exam' with your car which will be considered as a unique model itself which will cost you loads of money....
