We can't add anything. We're an independent site with no connection to Sony, PlayStation, or Polyphony Digital.
The developers do, however, read the site, so putting requests like this in their appropriate places has merit.
Car Suggestions go in the Suggestions/Cars forum. Note that cars you wish to suggest may have already been suggested and you should search before posting and vote for cars you would have otherwise made threads for:
It seems that making wishlists is a particularly popular hobby for many of you :D No matter what the thread may be, someone, somehow, seems to shoehorn a list of cars and/or tracks that they'd like in the game into it - and we have more than one thread that's basically a wishlist with extra...