My first question would be “How are carts stolen?”
My guess is that the thefts are not “local” to the community, wanna-be users stealing carts from those who already have them. My guess is that there are semi-organized rings traveling around with pickup trucks (or more likely enclosed vans, so that no one could see the contents) and the carts aren’t being “driven away”, but picked up and carted off by someone who will change whatever needs to be changed to make the thing no longer identifiable, and then resold – probably to an actual (remote from the community) golf course, where the user is far less likely to find his former cart.
If I’m right about that, then no amount of kill switches or other schemes to make the thing non-drivable will work, if it can be picked up, loaded onto a truck and carried away.
I doubt that every panel truck or van that enters the community (or more importantly, which leaves the community) is checked as to its contents, but that would be my guess as to what’s happening with them. (And please don’t tell me that “no one drives trucks here”, because in retirement communities people are always being moved in, or estate contents moved out.)