There is one forum member who put in the remote controlled cutout under the spare tire. That device looks very bulky.
I used cutouts on other cars in the intermediate pipes, under the car. It sounds great with windows open, but when looking for a little quiet, like when cruising on highway with windows closed, the resonation is a little much. I have put straight through magnalfows on the rear of the V, which I find good from behind the car, but too quiet inside. I am going to switch to small glasspacks, which I had on for a short time. I think the perfect exhaust would have a valve, like Ferrari and Mustang Cobra. Put on a mild resonator up front, or maybe just X-pipe, then put a muffler in rear with a valve. Quiet with valve closed for crusing, valve opens for straight through sound under acceleration. Just need to find a valved muffler that is small enough to fit...