1999 S500

I recently purchased a 1999 S500 with 54,000 miles on it. So far I have repaired an originally undetected a/c water leak driver side drain tube, driver side door check(stop), a stubborn glove compartment door, automatic door/trunk closing problem which was a leak near the trunk handle. I still need to tackle the non-functioning lumbar support. I also am considering having some sort of bluetooth compatible system put in while trying to use some existing phone wiring/microphone, and/or antenna and removing what is unneccessary. Any recommendations or comments would be welcome ? thanks