I did it on my 530, it's not hard. I ran the power wire through the headliner and brought it down through where the visor clicks in/out of then put the mount on the underside of the visor. Take it to a car stereo shop then.
http://photos.imageevent.com/scottpr...e/IMG_1155.JPG
http://photos.imageevent.com/scottpr...e/IMG_1150.JPG