Re: Alfa 75 2.5 V6 automatic.(??)
Had to change the tank on our 75 TS, which was the same tank as the V6 auto. With a 2 post lift and a helper it would be an easy job. Doing it on the drive is possible but will probably need a spare pair of hands when putting the new tank in. From memory there are no straps but the tank bolts directly to the car. There is an inspection cover under the boot carpet to get at the fuel gauge sender unit.
From memory mine has corroded through at the seam on the side where it is covered by the bumper. Seemed to be a bit of a mud trap (mine was a Veloce).
Biggest problem for me was the car had a tow bar, which had a mount running directly under the tank. So to do the tank I had to remove the tow bar and refitting that was a nightmare.
Oh, and final thought. After changing the tank the car had rather less range. Problem was the fuel pickup in the tank sat at a slightly different angle and hence didn't get to the bottom of the tank. Easily bent to fit (take out the fuel gauge sender unit and you can see it), but might be a surprise if you were not expecting it.
Oh, should mention I found a bag in the garage with the control unit and display panel from the Alfa control in it. Any use to anyone?
All the best