There's value in the ground vehicle model for explaining to someone how sailboats can travel faster than the wind propelling them. But I don't think sailboats are a useful teaching aid in the opposite direction; explaining how the ground vehicle works.

So unless the goal is to teach specifically about sailing, I feel it's best to leave it out entirely. Except maybe at the end as a passing mention like "BTW, this is how sailboats manage to sail faster than the wind as well."