My Alpine (way low end AM/FM/CD) did that too. I ended up cutting new square holes in the sidewall of the DIN opening, recessing the Alpine mounting sled in just over an inch, and snapping the tabs into my new holes. I also took the trim ring off and threw it somewhere in the woods. I think I saw a bird using it to make a nest.
_________________________
-
FireFox31
110gig MKIIa (30+80), Eutronix lights, 32 meg stacked RAM, Filener orange gel lens, Greenlights Lit Buttons green set