If your vehicle is showing raw gasoline smell inside the cabin, here are the most likely causes and the parts you'll need to fix each one.
A loose, missing, or worn-out gas cap allows fuel vapors to escape the tank. These vapors can easily waft into the cabin, especially when driving with the windows down.
The rubber seals around the fuel injectors dry out and crack over time, or get pinched during installation. This allows raw fuel to drip onto the hot engine, creating strong vapors that the HVAC fan pulls into the cabin.
Many cars have the fuel pump located under the rear seat. If the pump was recently replaced and the gasket or lock ring wasn't seated perfectly, raw fuel and vapors will leak directly into the passenger cabin.
The evaporative emissions system captures fuel vapors. A cracked vapor canister or a stuck purge valve under the hood can vent these raw vapors into the engine bay, which are then drawn inside by the climate control system.
A failed internal diaphragm in the fuel pressure regulator can leak raw fuel into the engine's vacuum system or externally onto the engine block, causing a strong gas smell under the hood.
The pipe and hose connecting the gas cap to the fuel tank can rust or dry-rot. This usually causes a strong gas smell near the rear of the car, especially right after filling the tank.