[SL8Brick]

Bruce,
If your goal is clean up the aero profile of the exh system, why not just go with the IPD turbo exhaust kit(or DIY w/FCP exh components)? You'd get rid of the resonator and gain some pipe diameter, all the while staying with OE components. And if you wanted to get even more efficient, you could replace the round OE turbo muffler w/ a strait-through bullet-style muffler. A small diameter bullet muffler could easily be tucked up inside the muffler well behind the rear bumper and covered w/ a louvered undertray.