This BMW E39 540i touring - owned by a CT Reader - now sounds absolutely fantastic, all thanks to a little cutting with an angle grinder. E39 540i exhaust systems have two silencers, one which contains the tail pipe, and another which is a dead-end. The dead-end is referred to as the ‘scuba tank’ due to the way it looks. The owner of this 540i had the scuba tank removed entirely, giving the car a much meatier sound at low revs.
However, rather than have the hole welded up, a metal plate has been fixed in its place. This means that when a little more noise is wanted, the plate can removed in around two minutes, allowing some of the gasses to bypass the silencer and backbox, giving the car an incredible sound.