My D17 has been driving now for about 18 months. My ex and I do not monitor or place limits on her driving. We expect that her driving is limited to around town trips, i.e. going back and forth to school, her job, and friends. We have taken the approach of trust until proven wrong and so far there have been no issues. D17 knows that we would expect her to notify us of any out of area trips and on the rare occasion that these types of trips have occurred she has asked us if it's ok. I think the more controlling you get the more resentment that builds with kids and the likelihood of rebellion. I would lay your expectations out with your son and leave it at that. No need to keep mileage logs. Just my 2 cents.
