I've been a Driver Instructor in CFR SCCA on and off for 10 years. In that time, I only had to send one idiot home and another one just quit (with encouragement). My overall experience has been very good with the CFR "system". Driver Schools are cheap, give you tons of seat time and free instruction from the guys you'll be racing against. What confuses me is these guys will spend a ton of money getting into the sport, but 75% of of the them are gone after a year or so.