Hi at all,
I would say the same as "Jocke88", the forum is like the way it is now, because as he said you can talk about your car without beeing only specific. I would say you can change some things, but not make manufacturer based forums. What I would personaly prefere is that you seperate car questions from engine and other problems. e.g.: in "Onroad Nitro Cars" you would only talk about cars and not about the problems you have with your engine and tires, I would seperate the cars from their technical side.

But that's only my opinion.
However all in all I would'nt make manufactuerers based forums.