My cars have 2 shovels in them year round. One foldable metal shovel (like this or this ) and the other is a collapsible plastic snow shovel (something like this ).

The plastic snow shovel is better at getting the looser snow out of the way quickly while the metal is better at breaking up and removing the hard packed stuff.

Actually, the plastic shovel was part of a pre-packaged car kit, similar to this one (it looks like they've modified the contents a bit since we got them). The nice thing about this kit is the snow shovel fits nicely inside the bag and the bag has room to keep a foldable metal shovel either inside or in its side pocket ... it also has plenty of room to add all sorts of stuff.

This keeps all the emergency gear in one, fairly compact, package.