ZZP stage 3 intercooler is made from a special material called Ultem, I priced some out through work (we buy lots of plastic) and they wanted $1200 for a piece 16"x24"
He has come up with a few other materials but none with the same strength yet
Here'* an intercooler cross section to get an idea.
The Ultem works as in insulator and keeps the ambient engine temps from creeping up into your sc while your cruising around town.
btw the heat exchanger is out of a ford probe