All I would want is some type of shrou. I mean road debris, plus salt and all that crap has to take some toll. Get a little gash in the casing and then expose it to the ellements...i dunno. I'm just skeptical I guess. Not trying to question everything, but I wonder what you would lose if you put it right after the cat, but before the muffler, heck even before the cat, just somewhere a little more tucked away without being in the engine compartment. Less distance to travel.

Andrew