When it came to getting help with parts - good luck. I called Volvo to see if the CD Changers from one vehicle would work in another. They told me to contact the dealer. The dealer had no information. When asking the dealer about the installation kits, I asked for the part number. They wouldn't tell me and asked why I wanted the part number. I was wanting to confirm that I had the right part. I had a couple of part numbers from mail order houses and wanted to confirm that the dealer was ordering the right kit. I didn't have a good feeling that the dealer was ordering the right item. As for which CD Changer fits the V40: My local dealer had one in his display case. This one had the following part numbers: CD-V010CHAS34W0187 (Manufacturers part number - Mitsubishi) and 9488925 - (Volvo Part Number). I had found two CD Changers on Ebay. One had the same Mitsubishi part number and the Volvo part number was 9488926 (This is the one I actually purchased). The one I actually received via Ebay had a different Mitsubishi and volvo part number. Both of these units I saw on Ebay came out of S80 vehicles. Therefore, I would suspect that any Volvo 10 Disc CD Changer would work - does anyone have any information that would contradict this statement? There is a 10 disk CD changer on Ebay right now. If you are looking for one, check Ebay and check Junk Yards. I picked mine up for $125 with shipping. The Mounting Kit for a S40/V40 is part number 30623222 and my dealer charged me $101.39. The kit includes the Electrical connector (You must have this - Don't try the installation without it). If your vehicle was pre-wired for a CD Changer, you are good to go with just the installation kit. If your vehicle was not pre-wired, you will have to get the CD Changer Control cable - I do not have a part number. One web site listed a harness kit (Harness Kit = 9452279 @ $29.67) though I don't know if this is what you want. There is also a cover that you can order to hide the CD Changer. This is 9164597-8. It cost $21.24. This goes over the CD Changer. I think this is a wise decision. I had to take a box cutter and make a notch on one end so that it was slide over the wiring to the CD Changer. The only other option is an additional 10 disk Cartridge. This is part number 9452189. I found this on Ebay too. Good luck.