The front fenders are made of fiberglass. Actually these are original items of those days. They where used as replacement for rusty original steel ones. In that period cars rusted badly because rust prevention was not yet invented.
But fiberglass is not very heat resistant and therefore I made two aluminium rings round the opening of the exhaust: one inside and one outside and in between some heat resistant material. I sprayed them black so they are not to much noticable.