I'll hazard a guess or two. There are some pretty unscrupulous used car dealers out there, who sell cars to people with little or no credit. They finance based on weekly payments. If the buyer is one day late with a payment, there is an installed device which can be used to disable the car until the payment is made. Or failing that, it's also a GPS tracker so the car cannot be hidden, making it easy to repossess at a moment's notice. This looks as though it could be such a device. It could be that such a dealer owned and sold the car at some point in its history and it was never removed. Here the law requires that the presence of and use of any such device be prominently noted in the contract and agreed to by the buyer. Use of one without that notice (and agreement) to a buyer is a criminal act which will subject such a seller to permanent loss of license, heavy fines, and prison. They are required to remove it when the deal is done. So it's highly unlikely, but not impossible, that this could be such a device that your seller was never aware of.
Another possibility is that it was part of an interlock system that wasn't removed. That's a device that requires (by court order) the driver to blow a .00 into a tube before the vehicle will start, used to allow DUI-convicted persons to drive to work.
It could also be of Russian origin, a device used to gather intelligence which will later be used to blackmail you into voting conservative. Or, if not Russian, to vote for Hillary. It would be obsolete now anyway.