It may seem crude, but you can just cut a square out of the tin over the top of the fuel tank. I did this on a 1995 Camaro V6 and the fuel pump was rite there. Took about 2 hours. It may be crude, but if your broke then its what to do!
Fishtails way too easily? If the road is wet or icy then yeah its rear wheel drive, but the only time that mine has ever fishtailed when it was dry was when I took an intersection turn at 70ish.
You did buy a Rear wheel drive sports car, they are going to fishtail in the snow. Buy some proper snow tires, and take it easy in the snow! If that's not going to work, probably the bus would be a better option.
Your car fishtails in rain?
I have a Camaro SS, and I can only get it to fishtail in rain if I am going way too fast around a curve, or try to get it to. Maybe you should look into getting decent tires on it?
As for snow, these cars were not designed to be driven in snow. If you plan on driving in snow, you should get a FWD or AWD vehicle.
I have a 2000 Z28, and yes it is horrible in snow with the stock 245r5016's (mine were summers as I had not intended to drive this car in winter, but was forced too), but I found smaller (205rXX16s) cheap, half wore out, winter Kumhos already on Firebird wheels, and this car was like a friggen SUV compared to before! I don't know if the torsen diff accounts for this, as I have actually had the same tread design on an open diff Crown Vic and was not extremely impressed with them. I went from being stuck very easily in 1/4" of snow and absolutely paralyzed by 1/2" of snow, to being able to drive through 4" of snow worry free.