I drove out of RMS just today with a cat back SS exhaust with cannon muffler. Bit louder than I expected (oval muffler is quieter). But I love it. Workmanship is excellent. Service was excellent (they drove to my office also).
In cabin noise is a little higher than I liked, but I think its just because its a huge difference to the quiet stock system.
Leigh/Alex said its sounds almost the same as a full
TBE. I drove around all night, just to keep listening to it.
I will go back to RMS.