#23, it has been my experience that more often than not, those things are raised and no one is in them. The windows are tinted, but not so much that you can't see in them during the day. But the biggest clue to me is if the air conditioner is running. Even at night, that thing would be a hot box without AC.
They can be spotted in the theme park parking lots too.
I like to think that it can crawl around like a big robo-security spider.

These were a double feature on last week's Turner Classic Movies' Underground (around 2am EST on Sat mornings - hooray for DVRs!). TCM doesn't reshow the Underground films on a regular rotation, but these will probably show up again in 3-4 months.
http://www.tcm.com/underground/

These were a double feature on last week's Turner Classic Movies' Underground (around 2am EST on Sat mornings - hooray for DVRs!). TCM doesn't reshow the Underground films on a regular rotation, but these will probably show up again in 3-4 months.
http://www.tcm.com/underground/

James Lileks would have a field day with this.