Having possibility to have different styles parts

I really would like to have different styles body parts for all Cars like stock lower specs and other levels of spec so I can make different models that are not In the game and it will be a good option to have more cars in game
Like chance to select between stock BMW bumpers and skirt or M-pack or Alpina for bmw or S-line bumpers and skirt for Audi
I explain with an example having bone stock bumpers and alpina bumpers on my e39 m5 so I can make more version like stock or M-pack or Alpina
bone stock bumpers on my Nissan Sunny so I can have a bone stock version or I can put a gt bumpers on it and having a GT not GTI-R

Would like to have that option for all cars like you done with some Audi