"Car" doesn't equal "preparedness" in my book. A car is just a tool. It might not be available. It might be impractical. It might end up being a liability in fact.

Looking back at Katrina, I'm not sure whether more cars would do any good. From what I've heard, traffic congestions were bad enough already.

In any densely populated area there is a limit as to just how much traffic the road network can handle at any given time. In an earthquake, major fire or something similarly destructive, the roads are likely to be blocked. Panic could take road rage to a whole new level. An SUV may look cool and has plenty of space for survival gear but it's pretty much all show, no go. If 4WD is a real necessity an old school Toyota or Land Rover will beat an SUV any day. In an urban environment though one might be better off with a smaller car, maybe even a bike. A big car needs a lot of room, not ideal when everyone owning a car is trying to drive the heck out of dodge at the same time. Just my 2 cents.