It really is an easy self install if you have a little mechanical aptitude (i.e. trim removal/replacement and plug and play wiring) and an ability to follow instructions. There's absolutely no need to remove as much trim as the instructions claim (just inside of tailgate and the bit of fixed back seat side on a 5 seat car - probably not even that on a 7 seater, and the centre vent and trim to get to the back of the computer) , and dealer will be quoting labour based on them.

I got the parts for the "factory retrofit kit" for UK£405 inc. VAT, and dealer charged me 2 hours labour for a full progman update prior to install, plus coding and calibration (special laser tool neededfor this) afterwards. Parts price was discounted, based on a comparison with Cotswold BMW who advertise on various owners sites....

Result is completely as per factory option, with full screen/PDC graphic split with camera view options, all graphic overlays, towbar zoom, etc.