Thanks Ron. I spoke with you on the phone friday about the Alumapro sub. I appreciate the help. Maybe you can help me on another issue. I am looking to putting a port from my trunk to my cabin and I saw a DIY where a guy cut out an existing perforated templat for the ski pass thru on a car that did not have this option. Do all BMWs have this pre-existing spot in the metal for a cut out. I seems like it would be a good place to do this. Here is the DIY link.[email protected] said:BMW has a breather hose attached to each battery at the bottom edge that exits out of the car.