Funny, we just had a call for a car fire tuesday night
1. Don't Breathe. There's lots of of toxic stuff, even deadly Phosgene gas if the air conditioning system is a freon-charged system. Get AWAY from the smoke unless you have an air pack on.
2. Don't approach without protective gear, esp. multiple eye protections. Tires, Shocks, Gas Lift Struts, and of course, the fuel tank all tend to go "Boom" when heated (as they did in this fire).
3. Don't assume that the ground all around the vehicle won't burst into flames instantly. There can be fuel all on the ground not ignited yet until some flaming plastic drips on the ground.
Just some typical stuff that we think about.