Heres a link to a video of my old My'13 750i. Miss the car so much still. Did a full 3" exhaust right feom the downpipes back. Was able to switch exhaust configuration at the back via V-Band clamps installed on the exhaust. In the video, i had exhaust dumps installed. So straightpipe with a 90• downfiring dump pumping exhaust towards the ground. Sounded nasty.
Youtube search DMAX745i, its on my channel. Seems link wont work through app.