Re Gas door:
I had the same problem with my 92' SSEI. The spring broke on the gas door and it would move around when I drove.
Go to RadioShack and buy a pack of small round magnets. I think the magnets come 8 to a pack. Buy a good quality gel based superglue and some rubbing alcohol. A gel based superglue will not run as much as the regular liquid stuff does. Just be careful when you use it.
In warm weather or in a garage, use the alcohol to clean two spots on the inside of the gas door (top and bottom near the door edge). The same for the body side of the door. Place a magnet at the top and bottom of the door. Do the same on the body side.Make sure the door shuts securely. Mark their location and carefully glue them into place. Make sure you get the alignment and pole position right. You want the magnets to line up and "attract" not "repel"! Because the magnets are small, you want to use enough superglue to ensure a good bond.
If you do this right, the magnets will line up and will keep the gas door shut up to "Go to Jail" speeds. The only drawback is when you go to buy gas, the door will swing freely since the spring no longer works. A small price to pay (less than $10) than getting a new door and having it painted.
92 SSEI, 137,000 miles.