Hi, I just bouth a S60R 2005 and I like to add a WMA CD reader to the HU-850 unit. Does any one have any idea how to do it? Will the Alpine CHA-S634 a good fit and how can I connect it.

 

Alpine changers have a new auxiliary connection. Not sure what it's called...but the old one was M-BUS. Either way, they're both pretty much compatible with only Alpine HU's unless you have a background in re-networking.