To break up or not?

I have been in a relationship with this guy for 4 years. We are 21 and have a really strong relationship. Our main argument is his driving. He thinks he is a great driver and well..I know he isn't. He drives too fast and he doesn't pay attention. He bought a 2008 Ford truck in last Oct. In Nov he rear-ended a bus and two weeks later he backed into a car. Today, he was doing a "doughnut" and rolled his brand new truck. Completely distroyed. Thank God no one was hurt but he is so non-chalaunt(sp?) about it. He is getting a brand new truck because he was covered with insurance. I am so fed up with his immaturity. We are both 21. I love him so much but I wonder if I break up with him if he will maybe mature a little bit. I really want him to be more mature. I am trying so hard to save money (his and mine) for a piece of property, trying to get us ahead but it seems like he just doesn't care, he just wants to be 16 and stupid. Am I being completely unreasonable to be angry?