Does stuff like Dry Gas or Prestone's gas line anti-freeze Work? Do I really need it?

Oh it works. When you get gas, it has a small amount of water, and what dry gas does it it bonds to the water so it can't freeze or cause you to stall. If ya'll need it depends on where you live and if you seem to stall a lot. If you live where its really really cold a lot of the time, it wouldn't hurt, but if you live where it only gets a little cold you'd be fine without it. If your car has been sitting for a long time and it stalls a lot, dry gas is an immediate quick fix to most of the problems.