Making a checkpoint system

I am making a gamemode and so far I have it where you push f1 to spawn in a car and if you die then the car removes it’s self. The trouble I’m having is creating checkpoints, I’m guessing you create a brush entity but i am unsure on how to make it know when a car has gone through it and which player that was. If anyone could help I would be very great full thanks

**[ENT.Touch

http://wiki.garrysmod.com/favicon.ico](wiki.garrysmod.com/?title=ENT.Touch)**