If you've had as many problems with the door bezels on the SV6 as I have (both sides, GM part numbers 15844058 and 4059) then you have replaced them several times - only to have the tabs break off again and again.
I recently solved this problem, and it's a relatively simple fix.
You need: a drill, with about a 1/8" bit that can drill into metal; a knife or X-Acto to create a beveled edge; the tools necessary to remove the door panels from the van; a screwdriver to tighten the screws.
Materials: I used 1 5/8" fine-threaded drywall screws to fasten the bezels to the door. I chose the black to match the bezel. A picture is below.
Remove the bezel (if it hasn't fallen off already) and then the door panel. You may wish to disconnect the switches, in order to totally remove the panel and get it out of the way - but some may be able to do it with them connected. Drill a hole in the round opening under the rectangular opening where the tabs go. Take the bezel, and insert the bit into the cylindrical support on the back, and drill through the bezel. Taking the knife, create a beveled edge that will closely match the head of the screw you obtained ( I used a drywall screw, as mentioned above, but others may wish to use a rounded head, in which case no beveling would be necessary). You should have a hole in the metal of the door at the round opening, and a hole in the bezel.
Reinstall the door panel, and reattach the wiring harness if you removed the switches; then reinstall the switches. Install the bezel and screw it down snugly. As long as the screws are long enough to grab tightly but not interfere with lock or window operations (the ones I chose seem to work very nicely), your bezel problems should be over and it looks like a factory job (to me, anyway)!