Hi all happy new year!Looking at tweaking the sound system and noticed that the rear passenger side has two speaker cut outs. The driver side rear speakers has two speakers installed. I want to add another speaker with low end punch to the passenger side that is empty.

Where is the wiring harness that would allow a plug in and what speaker would you all recommend? I want a litte more bass punch, am happy with the mids and highs.I'm thinking that the originals are all Bose, two fronts(at the door panels) two at the rear door panels and the three at the rear deck. Found a place for a factory CD and would like to add this bass speaker!

Thanks to all for your replies and help. Leon H.

Yes, there are 9 speakers in your C280. Only 8 are active though. If you look closely at the bottom of those speakers in from the trunk, you will notice the both outside speakers are labeled BOSE, and the second speaker you have on the left side is labeled High Fidelity or something like that. This speaker is for the pre-wired speaker phone if you have the cell phone installed. Which reminds me, does anyone know if it would improve sound to wire this speaker into the system? Or would it not be good quality with the stereo's speakers?
Anyway, I have also considered adding another speaker to the slot on the left, but haven't yet, and don't think I will... because I had a 10 inch sub with a 300 watt amp installed in the trunk. Power for the amp was taken from the stereo but bypassing the factory amp, and the sound was taken from the rear left speaker. VERY nice bass now. :) Any other questions, feel free to mail me.
DF