Well, since you have tools for the vehicle and camping gear already, I would make a list of things you would normally consider too heavy for a survival kit. Things that would increase your chances of survival or just things that would make a situation more comfortable. Two things I carry that fit the bill are a full sized shovel (one of the ones with a shorter "D" handle) and an ax. Do you need them, probably not, but they have so many uses and hatchets and kukris and E-tools can only accomplish so much. If you have to clear a downed tree from a road, you want an ax. If you need to move snow or mud to move a vehicle you want a shovel. Then how about boots, a decent winter coat and a rain suit. I would guess you probably already have a sleeping bag and stove in the camping gear, but if not I would consider putting them in your car. Together they'll insure you're warm and well fed. Just a few ideas.