Have you accidentally pressed a button on your keyfob...

[minimods]

Mr Tidy said:

Yes, I left my 123d with all the windows open one night!

Did the same First night in my new house too... luckily nothing happened to the car. Not done it before or since.

[FurtiveFreddy]

I could take the keyfob apart and disable it myself, but it is useful to have the ability to open it remotely sometimes so I'd rather not.

It just needs to be programmed to take 2 quick presses to work.

If that's really not possible, I might take one apart anyway and see if I can put something in there so it needs more effort to make contact. My 'told you so face' is being used way too often

[SignalGruen]

Yup, 335i Touring in the early stages of ownership - all windows down and pan roof fully open, must have been in that state a good 10 hours overnight - thankfully it was summer. Made sure I put my keys in a safe area and not leave them in my pocket after that.