more motorcycle tech needed,donor material for gas tank

i'm going with a different style of tank on my pan,i'd been looking for a old king sporty tank with no luck.After really looking over the bike,in a new light lets say.I'm thinking about building board tracker style tanks for it.For you not familiar there long thin tanks that fit on each side of the frame,like fatbobs.Anyway would like the outside of the tank as you view it from the side to be slightly curved out.I've got no way of making this curve in new material and i'm cheap so looking at car doors to cut a nice section out of to use for the outer skins.Any cars come to mind that are plentyfull,disposable,and with a nice curve for what i want?People look at you kinda funny when your looking at thier cars with a glazed look in your eyes in the walmart parking lot.

 

I know you said that you're cheap, but you can't spend $60 better than you can on Ron Covell's "Making Motorcycle Gas Tanks" VHS or DVD. You'll learn a LOT, in steel and aluminum, and using a variety of tools to complete the task. You'll also learn some tips on mounting the tanks to prevent problems down the road. It's a great video.

--Matt