You are right about Conti series, that is production based, thank you for correcting me. I should have more accurately put it as old ALMS and GrandAm series and now Tudor series. Any of their classes didn't/doesn't have production-based cars, with the exceptions I mentioned. Too many allowances and exceptions are being made.
Conti series is glorified club racing IMO, performance adjustments are ridiculous for pro racing, but there is so much interest in it I am amazed at the type and number of cars entering each race; I am definitely missing the point in that one
