They used a pick up from the airport service, and apparently the owner/driver was a relative of one of the senior managers. It was somewhat blatant, in the kind of questions he slipped in weren't quite in the zone for your typical taxi driver.
I've never experienced anything like the janitor stories, although I can well believe them, but I did once work for a company in LA, where I struck up some really interesting friendships with a couple of the janitors who were unemployed script writers. They had some stories to tell...
I've heard old stories of interviews where you park the candidate somewhere, and get the janitor to come by and drop something, or ask for a hand - and they see how you respond. Was it like that?