Q: Gas smell when car turned off. No leaks or anything 2010 BMW 328i

It sounds like you may have a leak in the fuel tank ventilation system that may be causing the fumes to escape from the fuel tank. This can happen when the venting tubes in the fuel tank are leaking or when something called a purge valve is leaking. This is likely related to your EVAP emissions system and something called a purge valve solenoid. The EVAP system prevents fuel vapors from the fuel tank from escaping into the atmosphere. The EVAP system collects and temporarily stores the fuel vapors in the charcoal canister. The charcoal canister is filled with activated carbon pellets that can absorb the fuel vapors. When the engine is running, the fuel vapors are purged from the canister and burned in the engine. The vent control valve (solenoid) controls the flow of outside air in and out of the charcoal canister. When this is not working properly, you may experience the gas pump shutting off prematurely causing it to take a very long time to fill up your fuel tank. This is due to the excess fuel vapor that is present when the purge solenoid is not working properly by releasing these vapors. The gas pumps at the fuel station have automatic sensors on them (for safety reasons) that shut off automatically when too much fuel vapor is present. I would recommend having an expert from Your Mechanic come to your home to take a look at your car to diagnose your EVAP purge solenoid.