Sorry for the delay in reply. But welcome and congrats on scoring a Mach 5 kit!
Materials are as follows: Bondo 801 professional glaze for the body work, styrene sheet for the fins (can't recall the exact thickness), Pegasus CL 1285 19" wheels, Detail Master wheel knock off photo etch, Detail Master seat belt hardware.
Lots of other parts, such as the rear view mirror, were fabbed out of old plastic trees from previous models.
Hope this helps!