I thought I'd snap a quick photo of my winter driving car kit:
Tarp, two snow shovels (teamwork for digging out faster!), folding saw (have you ever been temporarily stuck on a logging road because of a downed tree? I have!), rope, road atlas, flashlight, headlamp, flares, gloves, stylish ponchos, dog food bowl, dog food, emergency dog leash, duct tape, fire extinguisher, hand warmers, soap, hand sanitizer, first aid kit with knife and survival supplies, water, coconut water, coffee in a can, Coke -- note: I pack these drinks when I'm planning on driving over mountain passes but eventually reaching a warmer destination or otherwise don't anticipate parking my car in cold temperatures for a long time -- and the "nutritious but not so tasty I'll raid the bag and eat them when it's not an emergency" pumpkin seeds.
I also usually put together/throw in the car a bag of extra clothes, socks, sleeping bag and food -- the contents of that bag depend on where I'm going, and I don't usually leave that stuff in the car all of the time like I do this car kit.
Probably the most versatile -- and most used -- item in this kit are the shovels. I've used them for digging my car out of the snow, but I also use them when it's safe to do so (sorry if this is a downer) for moving dead wildlife off of roads and into the ditch or off the side of the road. It's an effort to reduce the likelihood that scavengers (coyote, vultures, eagles) will get hit by cars when they try to go to/are next to the dead wildlife (and save the folks driving cars from hitting those animals.)