Knee airbags are no new thing, though while many cars feature a driver's knee bag as standard it's less common for the front passenger to get a leg-protecting airbag of their own.
Why? Because of a couple of main reasons: airbags add weight, and the need to work around the glovebox makes it difficult to integrate an airbag on that side of the dash.
However Ford has neatly side-stepped both problems with its innovative passenger knee airbag for the 2015 Ford Mustang, which is integral to the glovebox lid and weighs 65 percent lighter than a conventional knee airbag.
Unlike a regular airbag which is made from a tough textile material and typically breaks through a thin section of the dashboard's skin, the Mustang's passenger knee bag is made of flexible injection-moulded plastic and is sandwiched between the inner and outer parts of the glovebox lid.
When inflated, it pops the outer part of the glovebox toward the passenger's knees, offering a small "crumple zone" to absorb any impact.
Want to see how it works? Check out the video above.