I want to install a 10" sub in the trunk of my 1992 300E. However, in this car I am not sure how to run the wiring. Does anyone who has done this have any advice on how to best wire the sub up? I still have the factory Becker tape player head unit, so should I hook up the wires from the amp that I got for the sub to where the door speakers are wired to? When I still had my 240D, I ran a power cable from the battery through the wire ducts in the floor to the trunk and amp. Should I do the same here in this car?

Thanks a lot for the help.