When I got my car in May last year the audio was intermittent, meaning it worked when I paid for the car...then stopped on the drive home. Eventually, I determined that the BOSE amp was at fault. So, what to do? I could, I thought, get it repaired for about £200, or buy a replacement used unit on Ebay with possible issues...but I couldn't find one anyway. At the same time I started seeing threads about fitting Android units to these cars...which looked very very similar to OEM...which was a good thing in my book. So, having read some of these threads to get my head around what could be done and what I wanted to do, I decided to purchase a unit and install a 5 channel amp to feed the existing speakers and to give a better sound than the unit’s internal amp. Having made this decision it was also clear that I would be ditching the entire fiber optic system for a hard wired system. No after market FO amps are available. This is the unit I purchased along with the bypass cable (more later): http://www.ebay.co.uk/itm/Android-5...425221?hash=item236e2ef005:g:mUAAAOSw5cNYY1zg Removing the existing headunit. This is easy on the w220 because it comes out forward, but more involved on the W215. But, thankfully, there are several how to videos on U tube showing how to do it. Here’s one: https://www.youtube.com/watch?v=dddHhPWhdT0 There are only two connections at the rear of the unit, disconnect these and unscrew the unit from the rear. That’s it…you will not be using either of those connections in the new install, so tuck them out of the way. The wiring loom When you buy the unit you will also have the option of buying a by pass extension cable to bring power from the back of the car to the new unit and for connecting the speakers to the new unit. Since I was not using the FO set up I had to buy this. There is an option to buy a FO interface to allow use of the existing amp etc…but this would only allow use of two channels not five…and I’m not sure the cd changer would work. It is possible to run the door speakers (not the sub woofer or front dash speaker) from the internal amp of the new unit, in which case you can use the by pass cable to do this…but you will also need to run a couple of other cables: A) You will want to run a cable to the unit to for the radio antenna. B) You will also want a cable for the GPS antenna. One is provided with the new unit…but the one already in the car will be superior. C) You can also run a cable to the unit for the original microphone for the Blue tooth rather than rely on the one in the unit itself. I placed the head unit on the kitchen cable and attached all the cables to the unit and then laid them all out and wrapped them in loom tape to make it easier when running the loom from front to rear. If you are not going to install a separate amp that’s all you need to do…though an RCA for a reversing camera should also be included if you are going to install one. I installed a 5 channel amp so as well as all the above cables I also ran three pairs of RCA cables, 5 for the channels and one for the reversing camera. Running the loom. I recommend removing the passenger seat…it is very heavy, but is only held in by 4 bolts. You will need to disconnect the electrics under the seat and the vacuum pipe. With this out of the way you will need to remove the rear seats also and the front carpet etc etc. As you can see there is a natural run for the new loom from the front to the back under the carpet…not along the side, there’s no room there. This sounds quite easy and straightforward…but you will get stuck taking out the rear seat back etc. If you are doing this just ask and I an give some pointers. The amp install. You will appreciate how compact the BOSE amp is when it comes to after market amps. I had to attach mine to the back of the boot: I stripped out all the boot panels. This way I could attach the amp to the rear panel, using a sheet metal plate on the rear to provide stiffness. I also made up a small loom providing connection to the speaker terminals so that when I re-installed the rear panel I didn’t have to fiddle about leaning in the boot to make each connection. You will need to include a connection for the blue remote wire to turn the amp on. The RCAs were long enough that I didn’t make a separate connection for them preferring to just but a hole in the back panel to run the cables behind rather than in front for neat ness. The battery being back make the live connection very easy. Buy an amp connection kit and it will come with an inline fuse. Again, both the earth and the live were long enough that I could pass them through a hole in the panel and cut to fit later. I removed all the stuff in the back of the car...Bose amp, Audio gateway, cd changer and DVD drive for the sat nav. When you have everything connected, except the earth and power for the amp, you are ready to go. Now…disconnect the negative from the battery. Make your negative connection to the amp and then attach the live to the battery…only then attach the battery negative back on. When I did this I got no sound because I had spliced into one of the blue remote wires in the boot from one of the discarded pieces of the old kit…but it didn’t provide the full13 or so volts so it didn’t turn the amp on. I had to then run a blue wire from the front to back to provide the required voltage. I attached this to the cigar lighter for a switched turn on. It then worked and all I had to do was adjust the amp to suit my taste. Conclusion It had been many years since I had ever done anything like this and it did take a couple of days to do…but well worth the effort. The best thing is to do your homework, loo at videos, get it straight in your head what you are going to do…then go at it slowly and logically. I have since added a reversing camera and it is easily as good as any I have experienced ion other cars where it is oem. The unit also has two usb outputs for whatever. I don’t know if I will use them but I did run two cables to the cubby under the arm rest where the HFP BT device used to sit…just in case. I sold the full Comand system on Ebay and, except for the amp which Santa bought, I made a little on the whole install. I accept that I may have been lucky since there isn’t always someone out there with a W220 wanting to install the later gear.