I've never done an overnight from one of these. I read that you have to stake your car so that plows don't damage them. What's the best way to do this? Do they actually sell stakes or do I need to make something myself?

I've slept at the park on Donner Summit a few times. You would only need snow stakes if you parked there a long time and/or it was going to snow alot. Stakes can be made of pvc water pipe with the top painted orange or red.

you might also, if you're sporting a spiffy pair of rims or nice new tires, make sure you have locking bolts. I was out for the day, parked at boreal and came back to find my clunker 87 cherokee (but with new tires) messed with––the CHP came by and told me it was a fairly common thing. THey'd tried to take off my tires on the right side, against the snow bank, but only managed to loosen the bolts up before giving up.