I just want to use this post to make a PSA - ALWAYS keep a blade in your car! In the case of a serious accident you may need it to cut off your or a passenger's seatbelt, as the locking mechanisms can get stuck and make it difficult to reach the buckle/release. Ideally you want to keep a "vehicle escape tool" which has a hooked safety blade and a punch for shattering your windows if needed. But the right knife could do in a pinch.