L'drop
A hidden hand-job done quickly in a moving car, usually somewhere near Chicago, and usually while the other person is too busy to notice.
"He gave me an L'drop in a moving car. I didn't even realize it until I got home."
"Got an L'drop while we were stuck on the highway. No one else noticed."
"She did an L'drop in the back of a moving car. I almost screamed."