Probably about 15 driving my parents' Pontiac on a little used gravel back road near our cottage. Said road is now paved and quite busy. It was a stick (3 on the tree) shift.
Age 16 driving a stock car on a dirt track until the officials wised up. You were supposed to be 21. The real driver almost got banned. The starter was killed a couple of weeks later and the track closed.
At 18 had my first car a 41 Plymouth coach.
Biggest enjoyment when I first drove a sports racer after a couple years of racing assorted MGA's and B's in various states of mods from street stock to fairly highly prepared. The A was mine but none of the 3 B's were which made racing cheaper!! :D
