Some say they are working on GTA Applethorn. It will take place in a city based on the actual city called Apeldoorn. Netherlands. Of course you will also be able to visit Diepenveen(Deepenvayne) later on in the game.
it is possible but you have to own the PC version and use a car modification programif you go on youtube type in gta carmods and there will be a vid of what cars you can get and also you can customize them as well