I had a gas smell once due to an egg-shaped gas filler hole; the mechanic fixed it by simply putting some channel lock pliers down the throat and pulling it back into round.

Trevor, make sure that the drain hose to the gas overfill funnel is draining outside of the car on the ground. Sometimes the line will pop up into the trunk and leak into the trunk "spare tire area". Maybe this will help. Take Care...
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Michael 'Street'... one AZ '85 244DL 185K miles

Seems I remember a metal "loop" with rubber hoses under a panel in the trunk that's part of the evaporative emissions equipment. If one of the hoses was to get knocked off you would smell gas at the rear, especially in the trunk.

Justin B.
83 Turbo

The gasoline smell around the rear of my '91 turned out to be simply the need for a new gas cap. The problem was probably exacerbated by the fact that my opening is very egg-shaped. A new cap fixed the problem.

check your gas tank neck too, remove the cap and look at the opening carefully, see if it has become egg shaped from the fuel nozzles. this is pretty common occurance.and then check all the hoses, from the neck to the top of the tank and from the tank to main fuel pump.

Trevor,
Check the seam on your gas tank,I had to replace mine because it was leaking there.
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philvo