I like the idea of a sleeping bag, but it does take up a lot of space in the vehicle. I love my Escape, but there's not a whole lot of space back there if you put in a sleeping bag.

I have two sets of those Adventure medical kits emergency blankets (Heat Sheets?), and although a sleeping bag would be much more comfortable to "sleep" on or in, from a warmth perspective, and being out of the wind, do you think that's adequate?