Well, the issue is more about things we'd like to leave in the car, but not necessarily have melt while we are away (crayons, candles, that kind of thing).

Which brand/type of sunshades do you recommend? We have one of those shiny metallic ones that fold in kind of a zigzag when you're done with them, and it does absolutely nothing to keep the car cooler.

I need to pick up some last minute things at Napa auto parts before we leave, so I'll check out the plastic things to keep rain out, too.

I'm wishing I were as trusting as my mother was when I was growing up: she just left the windows on her car wide open when it was hot, and the car stayed significantly cooler (a good thing, since it didn't have A/C!).