I don't think you know anything about drifting. Not trying to highjack the thread. But this is my point saying drifting isn't a muscle car thing is like saying auto cross, road cources, circle tracks, or the salt flats arent for muscle cars either. The 60-70s are over, no one has drag raced a bone stock car in any big time competition in 40 years (nhra, ihra ect.) So the "kids" with their non "muscle cars" have came up with new ways to have fun behind the wheel.
Muscle cars aren't limited to being built by the big three between 1960 and 1974 that was just an era that has past us by.