If mom and dad started checking the vehicles like my parents did, they could readily identify some of those racers. Burnt rubber usually clings to the undercarriage and doesn't come off completely in a quick car wash.. A simple check will open a conversation that counts.
Appropriate action (IMHO) would be "hang up the keys until the lesson is learned".
It may make the kids mad, but it may also save their life.
Here's a little edit: I don't know if the school does anything dramatic to make the kidsore aware of fatalities due to traffic accidents, but a few years after I graduated high school, we had the misfortune of losing five students in a single racing accident (two boys and three girls). I attended the funerals because they were brothers and sisters of my schoolmates.
I barely remember their names, but I can still see the five caskets in the same funeral procession.
The school hung a plaque with a picture of the caskets in the hallway. It had quite an impact on my younger brothers and sisters. 4951