mike knapp here ben a z car nut for 30 yrs have 5 in my back yard trouble is when they sit the tanks gum up with s--- and rust doses any one make a plastic nonrusting gas tank? let me know znap01@aol.com oh ya iam in hotlanta ga

They are called "Fuel Cells" and may be purchased from automotive performance outlets.

You might try adding fuel stabililzer to the fuel when you know they will be sitting for a while. It won't help the rust but it will prevent the gum up.