I have Eisenmanns Race on my vert. I did a minor change to it as it was for a coupe. I alterred one of the two crossover pipes that joins the two mufflers together as the vert has strenghning bars bolted onto the diff going forward & backward up underneath the boot.
Anyway I only have a small drone at around 1600 revs but at highway speed 60mph no problems can listen to the radio, talk to passengers, use the phone.
But when put your boot into OWG, damn that thing growls. Glad I did not buy the Sports because it would have been too quiet.
X5 F15 M50d White, 20"rims, Yellow Calipers, Ceramic Pads. Better off saying what it does not have and that's a B&O Audio System, otherwise all option boxes are ticked.