The case of the stolen license plate (or look both ways!)

So an interesting thing happened on Sunday night. My father was in town and came by to meet Ozzie. After meeting him (and falling for his reticulated cuteness) we decided to go out to dinner. We'd each drive our own cars with me leading and him following. His last words to me before I got into my car, 'Don't drive too fast!'. Mine in return, 'Don't drive too slow!'. So a few blocks later we got to the intersection that forms the purpose of this story. I was looking to make a right turn on a red light and was trying to make sure there was time for both of us to get through by looking left. Clear enough and I moved forward. And immeadiatly stopped just as a I hit a kid on his bike (10, 12 years old). Didn't hit him hard, didn't knock him over.
Quickly rolled down the window, 'I'm so sorry! Are you ok?!?'. He was. 'Is your bike ok'? He looked down and back and something was fouling his back spokes. He pulled it out. My liscense plate. He handed it to me and we were on our way.
Needless to say I felt terrible. Glad that he wasn't hurt but aware of how bad it could have been. I should have been more careful. Last night I got to see the corner again and I don't feel as bad. There's a fence blocking the view around the corner. I'd have had almost no chance to see him before he drove off of the sidewalk and in front of the car even if I'd been looking for him. Of course I'll be more careful there from now on.
But I hope there's a lesson for him too. If I was biking (or walking) in that situation I'd never assume that the driver knew I was there. I'd stop and make eye contact before moving in front of the car. I'd try to be predictable in my actions. I hope that he learned those lessons.
Now...how do I put the plate back on?