Keep in the car in case squirrel hunting breaks out? Ruger Single Six revolvers are a fine .22 for plinking or small game. I'm wondering why you would want this in the car though? Self defense? If so, there are several better options, in fact they may ALL be better options.
If this is for protection of some sort, I gotta agree with Fisherjohn. .22 LR can definitely kill someone, but larger calibers do the job more efficiently.