When I look at the back of my D1, it looks like there is a larger gap above the trailer hitch and the bumper (??) and the back door has started rubbing on the top of the bumper rubber pad. I know the other drivers that park behind me are not too careful and have contacted the bumper often. And I know that wonderful customizer (rust) has taken it's toll. Is it possible my bumper is pushed upwards? or the body is going downwards (rear body mounts sagging/ can i adjust the bumper to a lower level

 

the stock stamped steel bumpers on these are a little wimpy....especially for a vehicle that's supposed to be so off-road worthy............so in my experience it doesnt take much of a "tunk" in the back to jack the rear bumper out of place ( and rub on the door) . But, also your rear door hinges may be getting a little sloppy and allowing the door to sag some

 

Check your rear body mounts. They're probably toast.

 

I was thinking the rear mounts may be a bit squashed, Hinges seem Ok as I can't lift the door and it seems to align with the latch OK. This may be the start of the end for this poor rusty truck...