I tend to also think along the lines of gearing up to get help (AAA service, cell phone, cell phone power cord, watching cell phone battery levels, PLB, ...) and to be noticeable (large orange trash bags can be hung out a window and/or cut lengthwise and run over the roof from door to door for better aerial views.

My father used to buy brightly colored cars for visibility issues.

BTW, I carry a sleeping bag rather than lots of clothing, though I try to dress for the weather - under the assumption I'll need to spend some time outdoors - rather than just running from car to door.