Hi Sundance,
We start with broken TYCO Indy Bodies, cut them down to basically save the body mounts and flatten the top to glue sheet plastic to them, then cut sheet plastic sides and glue them on. The roof is also made with sheet plastic, shaped, cut and glued on.
If you look close you will see we even reuse the windshield off of the Indy bodies, cut down for the air cleaner guard on the hood.
We've build a few of them using the ferrai bodies (TYCO), if you look at the prev. post pictures, the #1 "Baby Ruth" White latemodel is constructed this way.
That's what happens when old guys play with little toy cars and consume certain beverages at the same time!
Later,
Warren