[Spridgets] Racing Spridgets - fuel cell.

[derf]

There are tracks you can get on here with cars in street trim.  But,
any large, organized group will have strict regulations and rules.
Insurance is expensive and things like roll cages, fuel cells, and
fire suits are often required.
There are economical options like SCCA and SPEC Miata where you can
compete without spending hundred of thousands of quid.
For example, the local drag strip is open to just about any street
legal vehicle.  But, if you run faster than an 11 second quarter mile
you need certain safety items not required for the slower vehicles.