I wouldn't. It would probably rub through eventually anyway. I would either have a muffler shop correct it, or bend the lip on the tank (if it's just the pinch weld it's hitting). The muffler shop fix is The Right Way(tm).
Mine did that too. I just pushed the metal hanger of the tailpipe through the rubber hanger as far as I possibly could then put some clamps on the metal hanger to keep it from working it's way out again.
i have the perfect fix for you. get your exhaust to be as loud as it can be. that way you won't hear the rattle. seriously though i would just try adjusting the mounting hanger.
I dont know how your exhaust is, but on my 88 if I loosen the system at the rear mid-pipe connection, I can rotate the catback and this moves the downstream pipe laterally.
Probably a completely different animal since that's a fox GT.
i backed into a curb last year and pushed the tailpipe into the corner of the gas tank, so i know exactly the noise you are talking about and it is annoying.
i took a rope and tied one end to a concrete light post and the other end to the hanger. then i slowly drove away to pull the pipe back. it worked, but a few months later, the hanger broke off the tailpipe and had to be welded back.
then about a month ago in the big snow storm we had on the east coast, it slid down the ice on my driveway in in the middle of the night and hit the curb, which pushed the tail pipe back, so it is doing it again.