Massage functionality in car seats is nothing new, albeit a bit extravagant. But this one really takes us by surprise. General Motors recently filed a patent for an in-floor foot massager.

First discovered by Carscoops, GM filed an application with the United States Patent and Trademark Office. The document describes using a variety of small air bubbles placed inside the passenger side floor. By inflating and deflating the bubbles, it massages the feat of whoever sits in the passenger seat.

The air pocket system is how a lot of massage seats work. While somewhat more complex than traditional bumpers connected to moving rotors, they’re cheaper to manufacturer and allow for discreet “flattening” when not in operation. Since it’s commonplace, the patent appears to be more about the location of the bubbles (in the car floor) than anything.

We can absolutely imagine this being a feature added to a larger luxury vehicle like the upcoming Cadillac Celestiq. Being exclusive to the passenger seat, we can imagine it being used by vehicle owners that are chauffeur driven, especially.

Like all patent filings, there’s no guarantee that the idea will ever reach production, or even if they plan to. But it does give us insight as to what various brands are planning.