I don’t know how this could possibly be safe at all.
It soaks up spare heat in the gases to do the cooking, and the clamshell design keeps those noxious fumes away from your food.
There is no way a burger cooked with exhaust fumes could even reasonably taste good, although it would be killing two birds with one stone. If you really want to be lazy, you can just leave the car running and forget about the driving!
