Car would not shift, but does now
 

Ok, my '91 740 Turbo has had some issues as of late. I recently went to a tire shop to get my rim replaced (as a previous post can tell you). A mechanic went to move the car and came back in saying that it would not shift. I went out thinking that he did not push the big button on the top of the shifter (auto trans). I tried shifting the car and it would not move. The SRS light was lit on the dash and then there was a loud, metal on metal screeching which I then turned the car off.
About 20 seconds later I started the engine back up and it shifted just fine and I let the mechanic take it from there.
I have not been able to duplicate the problem since and am perplexed about it. The only thing that I can think of that may have started the issue is after I rebuilt my turbo, I got the smallest guy in the college auto shop to steer the car while myself and two others pushed it into a bay so that I may install the turbo. The little idiot didn't realize that the BIG BLACK BUTTON on the top of the shifter makes it easier to move. The little idiot sort of made the shifter more loose than it was before, and this is after I replaced the shifting bushings. The bushings are still good and I did the turbo rebuild about 6-8 months ago.

Any ideas?