SO much bad info here.
First, keeping a bat in your car is a no-no. Yes, they can twist the laws unless you can articulate why the bat is in your car other than "self defense." Think ball and glove.

Improvised weapons are also a big no-no here, especially if they can prove intent (which is why I had to be notified of the laws by the clerk when I picked up a D-cell maglight at the hardware store). You can probably get away with a metal pen, but if you have to use it you may still get charged with using a deadly weapon.
Second, neoprimitive, your kubotan could be construed as a baton/club, and the whole setup may qualify as an improvised nunchuck. That's just possession, on top of what cuchillo states.
Strangely (for this state), pocket knives are legal to carry on your person for "utility" and double nicely for self defense. Pepper spray works too. In your home, or on the property of another with permission, you can generally carry uninhibited.