LOL at all the concealed weapon suggestions.
I had a BIG wrench in my car wedged by the drover's seat. It looked like another handbrake lol. I was never concerned about the cops..... "oops I forgot to take it out plus, it's a tool (you tool)". It had the parrot beak head so I could choose between blunt or piercing strike. Never needed to use it so I saw no need to peek it. Still prefer the unexpected punch in the mug and a bit of "Melbourne shuffle", if you know what I mean.
My suggestion, keep something like that in, make sure that it is innocent enough and hope you never need it and no one asks you anything.