About 56 years ago, my Dad had brought us (my Mom and my 2 brothers and I) along on a trip to a conference in State College, PA. It was summertime and the trip made for a nice vacation. Dad was driving a car from the University HE worked for, SIU, so there was a sticker on the rear with “SIU” and (I’m guessing) the campus’ fleet registration numbers on it. No University logo, tho’.
Anyway, Dad had dropped us off somewhere - I don’t recall, probably a park or something, and gone in to the conference that afternoon. When he came back out, there was an “Amish” youth sort of hanging around the car. My Dad guessed the kid was ~ 16 y’o. According to my Dad, he engaged the kid in some sort of small talk, then the kid asked Dad “What does “SIU” mean?
My Dad, never slow on the uptake, replied “Secret Intelligence Unit”. The kid’s eyes went wide and he sort of mumbled something to the effect that he (the kid) better get headed home. My Dad replied “That would be a good idea”.
The young man left quickly.
Today’s young potential car thieves are surely more sophisticated, but, the idea is still valid...