Some clubs might have a 30 year threshold on their private events, but from a historic racing and CAM's point of view, the threshold is 1981. Specifically Group T - Production Sports Cars with Competition History. This applies to Targa events etc and historic group racing. The government considers 30 years and over to be a classic car from a regulation perspective, maybe where the confusion is. As yet there isn't a modern classic class to cater for the 80's and 90's. They still compete in regular production sports classes. Which is not ideal really. 90's cars are not really competitive with the restrictions of the group, and it's probably about time a new class is created for modern classic racing. Also tech in the 80's and 90's advanced so quickly, you can't possibly mix it in with the cars of Pre '81 under the minimalist modification guidelines of the group.