I've just bought one from a breaker to put into my newly aquired BRM, have managed to source an adaptor on ebay that converts the R200's ISO connections to the 17 pin BMW style plug but have not as yet managed to figure our how to make the steering wheel controls work.
I read on another post on that the controls work through the iso connections and my lead has a couple of unused / missing pins but I'm not convinced as 2 spare pins dont seam enough for both the volume & channel / track
On the unit shown there are 2 further connectors beneath the main 17 pin block which look promising but every car audio specialist I've spoken to just looks at me blankly. I need to get to a breakers and see how Rover did it on the 25, the bit thats confusing me is I cant see any additional connections behing the dash, although the previous owner had fitted a sony head unit badly hence the change and may have cut the wiring. Can anybody advise me if there is a seperate connector / plug that went into the back of the original Philips unit
PS if you buy one you will also need an adaptor to change the aerialplug from an iso connector into a din
By the way you dont state the age of your 25, my parents 2000W Reg has a Philips RC Unit, but this has an ISO connection, the breakers where I got the CD player from had a 2003 25 which had the cassette version which lucked very similar to this and would be the BMW style wiring