During the winter I add my snow shovel to the cargo area just so it's always there. It's only for snow and the back country but it'll move some snow if you get your vehicle stuck. No need to mount it anywhere as I always end up needing to move something once I mount it.
I have this
SHOVEL.
For everyday carry I have one of
THESE.
It's a very nice shovel and works very well for it's size. For the most part I don't need anything bigger. On my other vehicle I carried a full size shovel and hi lift every single day and every single trip and never had to use them. The NATO shovel is small enough to throw in a pack if you need to hike out.
As long as I'm on the subject of other stuff I carry...I also like my
SVEN SAW. It's not very big but has cut some serious wood in the 8 years I've had it. Again it's in there all the time, not mounted (lies under my cargo mat), and can be thrown in a pack. In fact it comes with me on all my backpacking and Christmas tree cutting trips.
I also have a Maglight, Surefire, tools, tarp, fire extinquisher, tow strap, shackles but they all have their little spaces else where. I did cut out the interior of my rear cargo storage space to fit a bunch of stuff in there. Have a clean, non cluttered cargo area makes it easy to toss stuff in there or pack for a trip.