The issue with the convertibles at track events is the track insurance for the club. The current cost of track events is $399 for members which is pretty cheap. In the past, I was a member at both the Porsche and the Ferrari clubs. Their track events would only let you run in lower C level and did not allow for passing.
They are a bit more expensive, register with
http://www.motorsportreg.com/ and youc an see all the events near you. By the way the Peachtree Chapter was at Roebling Rd a few weeks back in Savannah and that track is a blast. The next event is at Road Atlanta in September and if you want to just reach out and I am sure we can get you riding shotgun with one of the instructors.