Cylinder Head Covers

I don't know how hard it would be or if it's even possible, but how hard would it be to make some cylinder heads covers and put them into the game? Obviously, you wouldn't be able to just drag it into the carparts folder as they're not like fixtures, but I think it would be cool if someone could figure out how to do this. I would love a pair of Edelbrock or Mopar cylinder head covers for V8s, just to give the engine a little more character and make it stand out more.