A large screwdriver would be far more dangerous as a weapon but they probably wouldn’t object to that. He could have a tire tool in the trunk and that would be okay too even though tire tools used to be a favorite weapon of the really bad boys.
Isn’t the car itself far, far more lethal than a pocketknife when used as a weapon?
Fine, whatever.
Then... the cop found my "stash"... of sport boomerangs. He asked me if I knew how to use them, and when I answered that I did, he said (and I am NOT MAKING THIS UP), "Well since you know how to use these, they could be considered weapons that you could use against an Officer of the Law. You should keep these in your trunk as well."
I have very little tolerance for cops now. Actually, make that ZERO TOLERANCE.