The Carb Cup still runs, which is the Nascar COT car on Charlotte, Daytona and Talladega. They are always busy.
It should be easy enough to get a race UK time in quite a lot of series. The Star Mazda is still very popular, the fixed HPD/Ford GT/C6R series is still very busy, and you can always get a race in the Indycar, either road or oval. The Aussie V8's got the NTM not long ago, and there is a European race organised, I think it's Sunday nights but you would have to check the forums.