I don’t have an urge to collect anything. At least not nowadays. So I don’t have an anecdote to share.
But I do have the solution to this problem:
It’s always a poor idea to set anything on a car. But if you must do it, set it on the hood in front of the driver seat, NOT on the roof. If you can reach one place you can reach the other, so it’s no extra effort.
You’re hard pressed to drive off with your briefcase, purse, phone, coffee cup, or take-out pizza sitting right there in front of you.
I’m pretty sure the blade would snap long before my folding locking one would close on my fingers. The blade is 1/1000000000th of an inch thick and the locking mechanism is 1/8 of thick steel.