Hey guys... fairly new poster here but I have been reading this forum for information for quite a while. I am wanting to get a sub for the trunk and use it with the factory sound system. I replaced the four speakers in the back because they were cracked from the Louisiana heat or blown, and I am happy with the sound, but I think it could use a little kick. I saw that Bavarian Autosport offers a plug and play sub package, but it's really expensive. I saw the wiring schematics from the Bentley manual, but didn't see a sub port. My question is - how can I hook up a sub to the factory system? I will stop rambling now. Thanks yall!