We, here in Slovenia allready have something like this... All things that we put on car, bigger alloys, bumpers,coils,lights, needs TUV appproval.
For example: u got mk5 gti , and u buy , 19'alloys, u need TUV approval from a firm that produces that alloys. And than u take car to technical inspection , so they can see that the alloys that u have on , are TUV approved for your car. Of course u have to pay 32€ for 1 part .So, if u have , like me , bumpers,coils,alloys,twintake,down pipe, catback,side mirror blinkers, u do the math, how much i had to pay , so i can have ''modified''car.
And than we have a document of a car, and they writte down any modification that u made on the car , and that is TUV approved.
Also , we can't have , de-cat's on our cars.it's illegal...If police catches u, with any part, with no tuv, they take your license plates + 400€ ....so , it's crapy , yea. ( hope u understand my bad english )