An intermittent starting problem. If you drive the car, park it and attempt to restart it 10-15 minutes later, it won't start. If you wait 3-4 hours it will restart fine. Cadillac service replaced the battery and it started fine for two weeks, then back to same problem. It has been in the shop for over a week and they only got it to fail once, so now have told us to come get it without having repaired it. Any suggestions.