So I got tired of the RDX being so quiet. I went to my local exhaust shop and changed that I has everything from behind the second converter cut out and replaced with 2 1/2" pipe. Underneath the rear axle is a y-pipe and I had new double wall 4" stainless tips installed. They fill out the exhaust slots in the bumper so much better. It has a great sounding deep tone with zero rasp and zero fart cannon sound. Under acceleration it is very noticeable, but at highway cruising speed it's barely noticeable. 

 

 

That's pretty nice concept 👍