cofi, the avvy shovel I have is an older Voile. Used to be made in SLC, not sure anymore. The handle collapses to appx 18 to 20" and extends to @ 36 to 40" (plus or minus).
Not that it would be perfect given your height, but many of the ski shovels work pretty well and fit easily into the trunk of a car. The other thing that surprised me I didn't see was 100' of 1500# rated rope (obviously assuming you have the extra space). I have used that more than a couple times to axle wench myself out of a ditch etc when I drove a Saturn, besides that you never know when it will come in handy. I also carry a set of tea-light candles. They don't take up much space and will generate enough heat to keep you alive in a car even if it drops to -40. It is always nice to be warmer, but the minimums will keep you going especially when you are tight on space.
Have you ever tried this? I made a four wick candle once and would light it and sit in my car when it was -10 degrees. It may be true that it would generate enough heat to keep you alive, but I don't think I'd use the term "warmer." At -10 below, I couldn't feel any heat from the candle until I was close enough to burn myself. So it's a good idea for life, but don't be under the impression that it will make the vehicle any were near "warm."
"There are no finger prints under water."
Sorry if I gave the impression that was any way to stay warm. Was saying it is a way to stay alive, but it is nice to be warmer (than what the candle can do for you). I usually carry those plus other things, but the candles burn long and with a space blanket will keep your core where it needs to be.
I had a father that would wait until we hit a really cold night, then we would go out and sit in the car and go through what you do to not freeze to death. At the time I really didn't understand why we were sitting in the cold, when the house was right there. Though these days I wouldn't trade the memories of freezing my ass off with my dad for anything.
That must have been miserable as a kid. Heh
"There are no finger prints under water."