Just spend the $10 or so on a new hinge, install the clip into the new hinge and put it on the door and put it all back together again. It's rather easy to do.
Had to do it on mine as the plastic hinge broke in a manner that kept the clip from holding the door open. It always wanted to keep the door shut. Was kind of annoying to have the door always want to be closed, even when you were filling the tank.
Cosmos Black/Black 1995 540iA M-Sport
BMW Individual Exclusive Edition, 1 of 65 total, 9/25/95 Build