EVERYBODY has that problem with the door bezels, the cheapest I can find them OFF of eBay is like $80 from Dalllasmustang.com
There are 2 little tabs in it, my passenger one has broken BOTH of them, and my driver is just missing the metal one towards the back.
Oh and I had to pull my cluster out a total of THREE times today. the first time I hooked it up to the blinker so it would flash when I signaled right, then I hooked it up to the fuse box and it STILL flashed so then I realised that it was the ground that was hooked up to the blinkers, so I drilled a hole in the HUGE metal pipe behind the cluster and grounded it there.
EDIT: Dammit I blew the fuse for my gauges.