Manufacturers often only offer leather in a model with a bunch of other features, such as a sunroof. Or vehicles with leather are in short supply. Or leather simply isn’t offered in a model. The usual solution: aftermarket leather.

But Automotive News reports today that GM has had to buy back 800 cars because they were re-sold with aftermarket leather. The problem: their passenger seat weight sensors, which turn the passenger side airbag on and off, were engineered only for the original cloth. These sensors were not functioning properly with the aftermarket leather.

Most new vehicles now have such sensors. In these vehicles, I would avoid aftermarket leather unless the installer can guarantee that the operation of the passenger side airbag will not be affected. Installers will likely be unwilling to make such a guarantee, as the potential liability is enormous.

So enormous, in fact, that GM decided that it made more sense to buy back the affected vehicles and salvage them for parts.