Cat protectors - namely cat shield for the gen 2 Prius - in my experience deter theft pretty well for the price. Cages don’t work bc they’re easier/faster to cut. A sheet of metal bolted in would require lots of sawing to get to the cat, more to cut it out. Takes too much time when they can just pick an easier target/ not get a bunch of sparks flying in their (likely unprotected) face.