I'd say a thousand miles or so, including a decent amount of time in at least mild twisties. Be able to keep up with normal speed of traffic on say 9 or 84. I'm all for getting out to the track as soon as possible, but I've seen people out there who weren't getting more than 5* off vertical, literally CRAWLING through turns... Like they would have been severly holding up traffic on any curvy road. They definitely could have used more street experience before heading out to the racetrack.