I would suggest transparent aluminum. But you might have to watch Star Trek IV a zillion times frame by frame to get the formula that Scotty typed on that computer! wink

P. Valdez

1998 VW Jetta TDI
1.9L I4 direct injection turbo diesel
5 speed manual
no mods, no money

AIM:PackRatTDI

My exhaust smells better than yours.