Busting the Midnight Siphonist

RAY: This puzzler is historic, folkloric, automotive—and, hopefully, not idiotic or pathetic. It was sent in by Laura Adamson. Laura writes,

"It took place in the early 1970's, during the first gas crunch, when there were long lines at gas stations, and Toyotas started looking really good to people who owned Detroit gas guzzlers. My friend Maryann lived in a rural neighborhood in upstate New York, and someone was sneaking around late at night in the inky shadows, siphoning gasoline, while the honest people were asleep. Maryann and the sheriff got together and hatched a plan to catch the thief. It involved using Maryann's car, and its full tank of gasoline as the bait.

Unlike many of her neighbors, Maryann did not own a locking gas cap, so her tank was very siphonable. The idea wasn't to catch the thief with a secret alarm, hidden cameras, or anything like that. They would catch the thief just by allowing him to siphon the gas and take it home for use in his own car.

The thief did strike and siphon her gas, and it was the end of the gas thefts.

The question is, what trap did they lay, and what was it about Maryann's car that made it easy to figure out who the gas thief was?

Think you know? Drop Ray a note!

[ Car Talk Puzzler ]