I don't know about others, but my rear license plate was just screwed into the plastic body panel. I like to use allen head bolts -- harder for someone to mess with my plates.

So I drilled out the holes, screwed in some threaded steel inserts from the hardware store, used some super glue gel, and now use some allen head screws, with plastic washers and chrome caps that came with the plate frame I bought.

Anyone interested -- local to Scottsdale / Glendae AZ, I'll do yours if you want.