Trisher123 - there are lots of model car racing clubs about. Both my boys went most weeks for several years either with me or their dad. They loved it. Lots of children from maybe 7 or 8 through to adults.
My boys made friends there. They were accepted, encouraged and supported in this mixed group. They are not children-specific clubs so check out the make-up first. Some obviously have more children than others. An adult would need to stay with him.
They had mini races, local club challenges, regional heats and even national ones.
The combination of the radio controlled cars and computers was win win win.
Our girls didn't take to it but there were a few girls there too.
You can search here for local groups:
www.brca.org/clubs
We bought second hand cars initially. They were hideously expensive then - I'm sure they will be more affordable these days.
Good luck!
Lack of public toilets in towns.