My main go to rescue knife thingie for my car is my 4 mo old Cold Steel M-21 ORANGE version. It also comes with a seatbelt cutter and the glass breaker on the back end of the folder body. My knive came razor sharp, was the 4 inch + version, and it resides in the pouch just inside my laptop bag.
seen 3 occasions with trapped people on the road and no knives in any pocket. The second time I had a small spyderco delica that took forever to finish the job, but this time, it will be different.
You should be able to buy one new for about $45 if you look around on line or some classifieds. Its not for EDC mind you, its for keeping in your SHTF bag, and for a paramedic or a cop carrying on the belt or in your vehicle where I can get to it no problem.