What I was asking above is were the warning lights in the car red or amber. The first stage of warning for brakes is amber - e.g. with 2000 miles to go to change, this then turns red when miles gets to zero. In my experience even when on red the pads had more than 3mm remaining (I measured them).
The warning should be separate for both front and rear - in mine you can individually see whether e.g. the front pads have 5000 miles left and the rear have 10000 miles left. You should be able to do this under idrive or using the OBC stalk (can't remember how the latter works).
Its odd how the BMW report said the rears needed doing but it seems that you hadn't had a warning light?
You should be able to rely on the car to tell you when it needs pads, not the dealer. Theres no need to rush when the amber light comes on either - plenty of time to change them.
Kwikfit shouldn't need a machine to reset the warning if they've replaced the right sensor.
PS Get a Porsche, you know you want to.