Hi
I retrofitted them on my 2004 Z4, I bought the parts I needed off ebay, switch, mirrors and if memory serves me right a control unit that goes in behind the glove box??? I went across to Peter Van Der Veer, over near Huddersfield who fitted mine, he even sorted out a loom extension for me. You will find a few references to him on here and If you like I have a phone number. It was all done one Saturday why I waited