Yeah, unfortunately I'd already made the second one from plywood by the time I found that article. I agree the ABS isn't super stiff; however, it works good for the Avenger's belly panel. But I think I'll get one of those for the truck; the aero forces I've seen pounding the front end are really something else. Polymetal:
PolyMetal™ - Aluminum Skin on Two Sides of a Recyled Thermoplastic Core Grimco (says they only do wholesaling):
Grimco - Substrates: Max-Metal, MAX-metal
I toyed with the idea of a similar ducting for my truck over 5 years ago, but had not clue how to execute it with what I had available in time and materials.
Interesting to see the exhaust wrap; wonder how often he has to replace the manifold? Exhaust wrap accelerates metal fatigue, as I understand it...