If you think about this however... Don't you think you'd want the best tool available in a real emergency?

I don't know about everybody else but I always pick quality, time proven gear for backup. A lot of folks believe a knife that doesn't hold an edge or is difficult to sharpen is perfectly ok for their BOB. As long as your backup gear is stowed away and never used it doesn't matter. But should you really find yourself in a bad spot all the details that don't seem important right now will become critical. And if your gear doesn't perform well it might make the difference between life and death. That's why skimping on your backup systems is a bad idea.

BTW, no knife with a revolving or somehow interchangeable blade works well for prying or digging in my experience. But the Japanese gardening tool is a good idea. So is a Woodman's pal. A small axe could be used for almost all the tasks you have in mind and it would be excellent at some of them at least. I don't think any of those options would look any more out of place in the back of a car than a big, exotic looking knife but then again, I understand your personal situation could be different. Best of luck and stay safe!