Transporting foam "boards" - Model Railroader Magazine

When I did something like this once, my Dad took two 1x2s, and secured them to the top of the car. The 1x2s were a little wider than the car. Then we tied the foam boards to the 1x2s at the front and back. There was lift and a scouring effect.

However, if I had to do it again, i would have wrapped the foam boards with a sturdy tarp, and perhaps sandwiched the boards between cardboard or light plywood.

It's times like this I wish I still had Mom's '73 Polara station wagon, which, when the middle and rear seats were folded down, could accomodate full 4x8 sheets.