What do you think about this?:
Regarding melting the rear bumper area around the exhaust outlet, one of the nice design features of my TRD Gen2 exhaust is that the outlet pipe tip is about 4.6" OD after the rear muffler but it has a stainless steel insert pipe in that last section that reduces the inside down to about 3.5" and with that air space between the inside flow channel and the outside surface, the outside does not get hot even after many laps of hard driving and even some shooting flames. An air gap is one of the best insulators you can have.
I'd say if your outlet pipe section does not have an air gap like that, and most don't, you could buy a section of thin stainless steel tubing about an inch larger diameter than your tip and long enough to extend out as far as you want (besides thermal insualtion, extending the tip a little will reduce the black soot buildup on the bumper) and back toward the muffler or front end of the pipe for about 8 to 10 inches or more, either tack weld the back edge to the muffler or maybe make three simple little U brackets that would support each end of the outer pipe over the inner pipe and tack weld those to hold it centered; polish the outer pipe, and you would have a nice looking very effective air gap insulator and with the front edge (toward front of car) open, it would act like a venturi sucking cooler air in from that end as the hot exhaust flows out the back. I'd use our laser marking machine to add a laser etched logo of the "Supra" right at the back for that last extra bit of HP.
