As The Cousins were making their way into the US to kill Heisenberg (Season 3, Episode 1), they turn their Mercedes in at a humble farm and take clothes from the line to swap for their suits, as the farmer (with a look) warns his wife not to interfere.
They then go to walk past the couple's daughter, who is with a tethered goat. One stops, looks at the girl, takes the car key from his pocket, and hangs it on the goat's horn, before walking on.
Did they intend to return for the car, or was this act a way of saying 'Eh, we took some clothes, but you get a car in return!'? I keep imagining them returning to find the farmer had turned the car into a chicken coop (or something else very practical).