If no gas actually made it onto the interior surfaces then you're only dealing with vapor which should be easy enough to remedy with a little baking soda. Sprinkle lightly onto carpets (when dry) then vacuum back out.
If the cabin filter absorbed that much of the odor though you might have to go more extreme and do an odor bomb. Meguiars has one now that I believe can be found in local stores and has been fairly well reviewed. Its a 2oz aerosol can that you activate, roll up the windows, close the doors and it fogs the entire interior of your car.
wirebender reacted to Team Adam's in After cracked fuel pump, my interior reeks of gasoline
