Four or five months ago I would have said www.yokomousa.com
but those guys have since stop selling in the US. I did hear of some talk of someone on this forum will soon be a yokomo distributor. Check and see if you can find his thread. I'll post it, if I find. Otherwise I don't know what to tell you. That is a pretty old model and I have not see one being sold on eBay or the likes...not even basic parts. You might have to check some online hobby shops that have been around for a while, like BrucknerHobbies, Stormerhobbies, Nitro house, and the likes. also look to some of the Europe hobby shops...I notice they seem to keep in stock, parts for older models, longer than they do in the states. Lastly I think there is a thread on this forum for that car...you might be able to dig some usueful info from there.