in our experiences, multi-brand/model sites dont do well, because you get too many fanbois who are only there to start trouble. for instance, even though the truck site is slow, we have ALOT of problems with people asking a question in, say, the dodge ram section...and there will be one good reply then several "your problem is that dodges are all junk...or one guy who replied to everything with "real men drive ford"...etc...
there may be a cuda site open soon though...
