Friend of mine just bought a 91 525i. Low miles, grandma-owned...literally. 77k miles. Interior is in great shape for what he paid, but it will need paint very soon. Anyway, when standing around the back of the car, there's a strong smell of gasoline, but we can't see any evident leaks. Is there anything else it could be? I checked the seal on the gas cap, and it seems to be fine.