If your vehicle is showing gasoline smell outside the car near the rear or fuel door, here are the most likely causes and the parts you'll need to fix each one.
The gas cap may be loose, missing, or have a degraded rubber seal. This allows fuel vapors to escape directly at the fuel door, especially after a recent fill-up.
The metal pipe or rubber hose connecting the gas cap to the fuel tank can rust or dry-rot over time. This leaks vapors or raw fuel, particularly while pumping gas or when the tank is full.
The EVAP system captures fuel vapors to prevent them from reaching the atmosphere. A cracked charcoal canister or a stuck vent valve near the rear of the car will vent raw fuel smells to the outside.
If the fuel pump was recently replaced, the rubber O-ring or metal lock ring on top of the gas tank may be pinched or loose. Fuel sloshes out of the top of the tank when full or cornering.
The fuel tank itself may have developed a pinhole leak due to severe rust or an impact from road debris, causing a constant raw fuel smell and potential dripping.