Snap! But I fitted the "Factory" retrofit kit (as if that isn't an oxymoron!)

Didn't take any pictures as it's all in the instructions posted elsewhere on this site, but suffice to say it only took me a couple of hours and you don't need to remove anywhere near the amount of trim that the instructions list - the wire to the front is so thin that it easily just tucks under the door trim, and can be fished through the rest of the way with a wire coathanger (perhaps this should be a BMW special tool?)

Still have to pay the dealer for coding, but that's my choice. I've saved 4 hours at UKP£108 per hour after all!!