Personally, I just don't get it. With shoes on, I'm 5'11" and I have my drivers seat pushed all the way back to the second-to-last position. And I'm not rolling around like an OG driving a hoopty, my seat back is quite vertical. When I'm out on the track, the top of my helmet just barely brushes the headliner.
It amazes me that you fit at all, let alone enjoy the car.