I am not sure what different types of gas intake systems there are, but my sentra (carburated) had one which floated on top of the gas, probably on a vertical rail of some sort (I never actually took a gas tank apart). I assume it just stuck on that rail because I sat for so long idling, and maybe some more gas evaporated while I was eating dinner, so when I went to start it the level must have been just below the float.

I would assume most cars would have some sort of floating intake - otherwise you would be sucking debris off the bottom of the tank. I have never really researched it, though.