Just a thought....whats the chance of your roadrunner gaining or having a slight body sag from sitting over time. Perhaps a slight sag would be just enough to produce enough pressure to pinch the door mech tightly into place. I've heard of many drag cars that couldn't re-open their doors after a run from body twist movement. A block of wood and jack under the door frames lightly lifted may reduce any mech binding (if any)...
As stated...Just a thought :dontknow: