I can relate to your stress, my guy got his license 3 weeks ago. We set him up with a small truck and had him pay for his own insurance, this way if he screws up, he pays, not me. This is the first week he is on his own, finally convinced mom you got to let go sometime. The upside, he started working a year ago and had to be picked up every Friday night at 10:30 (read:No Friday night beers with the buds and home early). Also had to get up Saturdays at 7:00 am to drive him to work. I may enjoy watching him drag his own butt out of bed tomorrow morning. Added bonus is the gas savings for me. Next plan is to get him to driver his sister around, (like that's going to happen). She's the one to worry about, been saving her money for 2 years to buy Mustang when she gets her license.
Good luck with the kids.