[Doubting Thomas]

I have recently purchased a BMW with auto stop/start engine. Has anyone actually got one, where the engine remains stopped (at traffic lights) for more than 1 minute. Mine keeps cutting in on its own. It has been back to the garage several times though they can't find anything wrong with it, even though the service manager has experienced the problem several times in my vehicle. I am interested to know how long other vehicles are remaining 'stopped' as I have been told mine is working correctly, though I don't know of a traffic jam that lasts only 2 minutes!!!!