Raw fuel smell inside of car

I just took my car to the chev dealer to have it inspected for any kind of gas leak. It is not an exhaust smell but a fuel smell. It seemd to only do it when I remote start my car first thing in the morning when the temperature is about -8 (celsius)& I have the heat on high. The smell is so strong that I have to open my windows to breathe. Usually by the time I drive about 5-10 minutes or so the smell goes away & does not come back until the initial start the next morning. The dealership found nothing wrong with my car at all & cannot seem to be able to smell the fuel as the temperature wasn't quite cold enough that morning. Very frustrating! Any ideas?