If you really plan to bug in in an urban environment, I suggest a small oxy/acetylene torch rig. Learn how to use it first though. It can be used for welding/fabricating(welding metal doors shut among other things) and/or cutting(like if you need to cut your way into a locked gun store or something). Much less labor intensive than trying to smash your way in. I do a lot of A/C work, so I keep a small rig in my truck. My vehicle is my "bug out/in bag of first resort".