Hubcaps?

I just got a very strange wrong number…"I'm looking for some hubcaps." Really? I know little about cars, but when was the last time cars used hubcaps? Back when I was a kid in the 1970s, "stealing hubcaps" was the archetypal activity of juvenile delinquents, even though I had no idea why anyone would actually want to steal them. Was there a lucrative black market for hubcaps back then? Today, though, perhaps there could be. Or maybe that would be an antique store. 

Also, too: all those UFO photographs you used to come across every now and then seemed to have stopped about the time the auto industry phased out hubcaps. Coincidence? Read the book!