baby car kit?

Cynthia • 22 | girl mom 💕
i'm not due until january, but i've been thinking about putting together a little car kit of things for the baby just in case in both mine and my boyfriends car. 
do you all think it's a good idea? what wouk you recommend to be put into it that won't melt/spoil/freeze?
just as a precaution in case either of us forget the diaper bag or the car breaks down for some reason.