you got one chance of a hit with a baseball bat IMO... you miss or dont connect and you aint got chance for another swing.

its also not practical to carry inside the car.. and not much use anyway.. as you get out say car jacking etc... what ya gonna do??

just seems bit OTT imo.

weapons only really good for a threat unless you really really willing to go for it and take the consequences.
you use a bat on someone who hasnt got a weapon and youre going to get put away. (unless of course they are breaking into your home etc)