Hey, I’m definitely missing bass in my BMW E88 Bj 2008/08.. Is the underseat woofer much better than most other cars but that’s not enough for me Now what could I do?Replace the underseat woofer(By which? ETON? Audi System? Others?) and operate actively(Which power stage?)? or simply connect/separate to the trunk/separation to the interior a bass roller(could you put into the trunk separation)/Subwoofer/Box(Could you be fixed to the trunk separation But that’s the smallest problem. I’m happy to have both of them, but which power stage would I need to run by 2 underseat woofers and one e.g. bass roller in the car? & Which bass roller or box? Crunch always seemed to me to be a good brand –> http://www.ebay.de/…/271770355447? ? Good? or https://www.just-sound.de/…/ in front of it? The dimensions of the boot opening are about 30*23cm wide / long (see photo) The disadvantage would be that the Lucke must also be open on the back bench (see other photo)..Wouldn’t bother me because you rarely drive with full crew. Only what would be if subwoofers at and opening too? Drowning or something I think? Have asked with ACR but then already wanted a small fortune..Maybe someone is in the vicinity Münsterland/Niedersachsen/NRW who knows about it and what to earn about it I think good hobby knowledge n is enough if someone has already done this with himself.. Also professionals gladly hope someone can answer all my questions and give me perhaps the installation greeting Marvin