Attaching trim tightly but not permanently

[Geesie]

I got my headlight bezels stolen back in November. Damn things are expensive and hard to find. Finally found replacements on eBay, getting them soon. I want to know if anyone knows of a way to affix these things to the car well enough so that someone can't just pull them off again, but not so permanently that I'll destroy something pulling them off to repaint the car next year or so.

Ideas?

 

[85 Cutlass Brougham]

What model of car? I would think some Robertson screws (square head) would confound them enough to keep the thieves at bay. I plan on using them to attach the subs in my car to keep thieves from them (and using nylock nuts and bolts to bolt the box to the trunk floor from inside).