I used the same method as Rick above. Except I used a large towel with a waterproof backing and a hole cut in the center that was the size of the gas intake. But I don't think I ever got a drop of gas on it as I just let it go in at about half speed. And the waterproof backing was made into the towel some way so it didn't scratch the paint. It felt as soft on the bottom as on top.
Ron