I have a 2012 x5 diesel. I was getting diesel today and when trying to fill up the diesel nozzle would not go into the fill pipe. After checking out why, I noticed the 'silver coloured' plate/flap in the filler pipe was not opening. I have filled up at this same station and others before but this the first time this has occurred. After trying to lock and unlock the doors no luck. Then was about to leave and one more try with my fill up routine and it opened like usual. I filled up and when i gt home to check the flap, it seemed to open up fine. My question is what could have caused this to occur and how does the 'misfuelling restrictor' as labelled on the gas cap door work. Thanks.