THAT sucks!!! I bet your really pissed off about that to say the least.
4ft track will be wide enough just try to make the quick turns slightly wider.
ukmicro rc has some videos on site of the indoor 1/18 scale racing, it is of road but it will give you an idea of whats required.
Have a look at this 1/14 scale, its a beauty
http://www.horizonhobby.com/Products...ProdID=SWK1460
The moongoose will pop in there too.