This post is just to help contribute, as I've gotten a lot of help from forums. I have a 2006 s500. It uses the Command NPT 2.0 with the MOST fiber ring system. What that means is everything in the infotainment system is connected with a fiber optic cable. The telephone, radio, navi, CD changer, Bluetooth, teleaide and SAT are all part of a fiber optic ring that's hooked in series. If one item is broken from the series, the fiber loop will also be broken, and you will not get any audio. If you want to add bluetooth sound, here's what you need to do:
1. Buy a module like Dension or GROM. those are 300-500$ and install it.
2. mr12volt bluetooth adapter. (what I used. $150 off ebay) -steams music, and takes phone calls.
note: These cars have a bluetooth dongle you can buy, but the bluetooth dongle will NOT stream music. it will work fine if you just want hands-free phone calls. If you plan to add any of the 2 options above, I would not even bother getting the bluetooh dongle because either of those options will give you hands-free phone.
Here's how to install it:
Principle- the mr12volt module will replace your CD changer. You need to switch to your CD changer in the command infotainment system. the mr12volt module will emulate the CD changer, but instead, you can connect your phone and stream music. You can even receive phone calls and answer them using the steering wheel buttons. you can also change the track and control the volume using steering wheel controls.
Installation (took me less than an hour):
Installation may vary if your CD changer is in the trunk, or up front where the radio is.
1. Buy module. I found mine for $150 from ebay. It arrived in 2 days to California where i live.
also buy a 3.5mm extension cable (male to femle works) . I needed another 3 or 5 foot to run the mic.
2. I went to the trunk and located my CD changer. It's on the left, drivers side behind the panels.
a. connections on my CD changer were the Fiber plug, and 3-wire power plug. brown, orange/red, and another color. (you will only need brown for ground and orange for power)
3. Remove your CD's from teh changer.
4. Access the rear of the CD changer by taking apart 3 or 4 screws that hold all the devices together.
5. carefully unplug the fiber cable from the CD changer. be careful not to crimp the fiber wires, or they will be damaged, and your radio wont work.
6. On the "mr12volt" module, you will need to use 3 harnesses.
a. MIC for the bluetooth phone capability.
b. power plug (blk and red wires).
c. fiber plug
7. plug the fiber cable from the CD changer into the "mr12volt" module.
8. splice the brown wire from the CD changer to the black wire on the "mr12volt" module
9. splice the red/orange wire from the CD changer to the red wire on the "mr12volt" module
10. mount the module somewhere so that it's not completely blocked off by too much metal for a stronger bluetooth signal.
if you dont want to use the phone feature, and just steam music, you are done. enjoy. Below are steps to run the mic wire if you want to use the bluetooh phone features. Replace the cover you removed to access the CD changer if you are done. Leave it off for now if you plan to run the MIC wire.
11. go to your back seat and reach under the left and right side lower cushions to press the tabs towards the sky. this will release the back seat cushions.
12. lift up the front and pull the cushion towards the front of the car. There may be some sticky brown adhesive on the bottom of seat, just peel it back.
13. undo the 3 10mm bolts on the bottom of the back cushion.
14. from the bottom of each side, lift up on the back cushion until the top of the back seat is unhooked.
15. on the right side, you will be able to see the trunk. this is where you will run the mic wire. from the module, down the rear back rest, under the cushion, under the driver rear door sills, up the B-pillar seals, and along the top of the drivers side front door.
16. tuck all the wires into the edge of the doors. They should be completely invisible. I used a plastic trim tool to gently push the wire in.
17. the final location of the mic is on the A pillar, just to the left of the sun visor.
18. re-install the back upper and lower cushions.
19. Replace the cover you removed to access the CD changer
20. follow the instructions to pair your phone.
pretty easy. Hope this helps someone.