I also have a good bit of gear in my suv, (no trunk--open back) spread around in the "nooks and crannies," which I supplement with whatever seasonal things I might need. I keep a collapsed back-pack hidden with the spare tire, so I can pack what I need (or everything), if I have to abandon the car.

I do not keep everything packed, as around here, one of the favorite petty crimes is to use a spring loaded punch to pop your window and then grab everything loose. This happened to a friend and they even stole his mud covered work boots from his truck. I really don't want to come back and find my BOB gone. If nothing is visible, there is less chance they will take the risk on my car when there are better targets in the parking lot.