Luckily I have a video camera watching the front and it turns out while the council workmen were strimming the grass across the road the flicked up a stone and put the window through. Thanks to the evidence I can claim my £75 excess back but it is the inconvenience of removing glass from the car for the next few years at least.
Another thing I am not happy about is the alarm did not even sound when the glass was broken so will be having a word with BMW about that.
Apologies for the crappy pic it was taken from the video camera as I was moving it down the drive out of the rain.
