Hmmm... good point. I'm thinking "out of site, out of mind". I don't keep anything in view in the truck aside from a cable lock for my bikes, and a few stuffed animals that the dealer gave me when I bought the truck (and of course, a big pile of PowerBar wrappers) -- no pile of CDs on the seat for me.
When surfing, I park in a parking lot, sometimes with attendants, but more importantly, people who have lots of other stuff in their cars. Heck, I've parked next to top-down covertibles with stuff sitting on the seat. Out biking, my truck is usually parked 40 minutes into the middle of nowhere, so the chances of any but the opportunistic pilferer happening along are unlikely. All the rest of the time my empeg comes with me.