The trunk kit sounds paranoid, but I've actually had occasion  to use my own kit, so generally pack it.     Mine has a shovel, a space blanket, some pocket warmers, some energy bars and snacks, and a large neck bottle (for emergencies!).     I was once stuck on the 400 for a couple of hours in minus 15 weather with a car full of kids and this came in very handy.

Snows should be a requirement IMO.      My pet peeve:   SUV and AWD sedan drivers who seem to believe that their AWD system allows them to brake and turn better (so they tailgate and go into corners too quickly when it's slippery).     I've been driving AWD since my first AWD car ('92 VW G20 Passat Synchro) and every car handles differently in winter.    AWD tends to push in corners when it gets slippery.      

If you can find an empty parking lot after a snow storm - go in late at night and practice skidding.    Do donuts, try panic braking.     This type of practice will save you from an accident one day.