A mate of mine when we where teenagers,we persuaded him that when the examiner got in the car, reach across and pull the door handle,to ensure its properly closed.
So Steve had his test next day,examiner introduced himself,and asked Steve to drive off, suddenly Steve remembered what we had told him and leaned accross and pulled on the door handle when stopped at traffic lights, when asked ,why, by the examiner, Steve said because the door doesnt lock sometimes, and i was told to pull it to check it was shut properly.
Instant result, test failed, and cancelled, due to serious safety concerns,examiner got out and got taxi back to test centre,Steve had to walk home, as he wasnt allowed to drive,being a provisional driver.So said the examiner.
Oh best of luck.