Trust me, it doesn't matter. It's like assuming a tennis star will be good at ping pong. Sure they may do better than an average novice because they have some basic skills but top-flight players will still be in a whole 'nother league.

The truth is yes, the guy in the Miata will be faster if he's a regular (20 times a year, not 2 is more normal for the average top-level autocrosser). In fact road racers in general make poor autocrossers because they aren't used to maximizing a course the first time they drive it and too often goof up the speed vs…