Pros and cons of moving gas filler to the trunk

Seriously, if you have a fastback Barracuda, you do NOT want the filler in the trunk. There is NO separation between the trunk and the passenger compartment. No, that dropdown panel doesn't seal airtight, and it wouldn't matter if it did, because there is a connecting vent behind the side panels. I wouldn't do it anyway, because pooling gas in the spare tire well doesn't seem like a great plan, either.

As Alan said, you can't leave the nozzle unattended. It's just the way the filler pipe seems to work. You have to back off the flow rate as it gets full, and don't try to top off. In my part of California, the big floppy rubber hood thing makes it impossible for the nozzle to even stay in place without pushing on it.