Likely an exhaust leak
There are several things that could be going on. The most common thing that would make your car smell like gas when the heater is on would be a bad heater core.
make be there is a gas leak
because you spilled gas in it
If you have a motor other than the car such as a lawn mower in the trunk it smells. Also if you just got gas it smells.
Fuel pump
It smells terrible it smells like old gas from the car when people smoke their teeth get ruined
Varnish, or in other words it does not smell like gas, it smells almost burnt
my car smells like i have a petrol leak when i turn it on but have no leak underneath the car
Usually gas smels like rotten eggs when the gas is too rich with additivies.
got a 2003 trailblazer and you can smell gas when stopping at a corner our when you get out of it
car smells of gas inside and out
too much fuel in your cylinders!