I wouldn't even drive it another foot, if I could avoid it. Get it to a mechanic. It's clear that gasoline is leaking somewhere.
because of the exhaust
make be there is a gas leak
If your car smells of petrol inside, and you have not been using a petrol-like solvent to clean something inside the car, you probably have a fuel leak and should have the car checked by someone able to detect and fix a leak.
because you spilled gas in it
If your car smells like the inside of a smelly gym shoe, you might need an air ionizer. Not only will it remove the offending smells, but it also works to clean and purify the air inside your car.
car smells of gas inside and out
It is possible that the heater core ( the device that heats the air inside the car) is leaking. It is connected to the engine cooling system.
It could be a bad fuel pressure regulator.
Depends on the smell. if it smells sweet, like antifreeze, then it is probably a leak in the heater core. This is a small radiator that runs from the main radiator and makes hot air for the heater. If it smells like gasoline, may be a gas leak. Do not drive the car, get it fixed by a professional. If it smells like smoke, it may be an oil leak. get it checked.
A smell inside is usually a bad evaporator coil.
may be pre-cat exhaust leak.
The area by the fuel filler should have a label reading "either diesel only" or "unleaded gasoline only". The area around the fuel gauge should have something like that also. If all else fails open the fuel filler cap and see what it smells like.