The Supreme Court’s recent decision in Impression Products v. Lexmark International was a big win for individuals’ right to repair and modify the products they own. While we’re delighted by this decision, we expect manufacturers to attempt other methods of controlling the market for resale and repair. That’s one reason we’re giving this month’s Stupid Patent of the Month award to Ford’s patent on a vehicle windshield design.

D786,157 is a design patent assigned to a subsidiary of Ford Motor Company. While utility patents are issued for new and useful inventions, design patents cover non-functional, ornamental aspects of a product.

Unlike utility patents, design patents have only one claim and usually have little or no written description. The patent only covers the non-functional design of a certain product. But design and utility patents are alike in an important way: both are intended to reward novelty. According to U.S. law, the Patent Office should issue design patents only for sufficiently new and original designs. By that test alone, it’s easy to see that the windshield patent should never have been issued.

Why did Ford apply for the patent on its windshield design? One possible reason is that it’s the automotive industry’s latest attempt to control the market for repair. If the shape of your windshield is patented by Ford, then no one else can replace it without risking costly patent litigation.

Ford has a troublesome history with independent repair shops: in 2015, it sued the manufacturer of an independent diagnostics tool under Section 1201 of the Digital Millennium Copyright Act, the infamous law that makes it illegal to circumvent digital locks on products you own. Later in 2015, the Librarian of Congress granted an exception to 1201 for some forms of auto repair, but manufacturers have continued to seek out creative ways to close out the market, whether it’s through copyright, contract clauses, or patents.

In the Supreme Court Lexmark opinion, Justice John Roberts specifically noted the danger of automobile manufacturers shutting out competition in the repair space:

Take a shop that restores and sells used cars. The business works because the shop can rest assured that, so long as those bringing in the cars own them, the shop is free to repair and resell those vehicles. That smooth flow of commerce would sputter if companies that make the thousands of parts that go into a vehicle could keep their patent rights after the first sale. Those companies might, for instance, restrict resale rights and sue the shop owner for patent infringement. And even if they refrained from imposing such restrictions, the very threat of patent liability would force the shop to invest in efforts to protect itself from hidden lawsuits.

If the Patent Office continues to issue stupid design patents like Ford's windshield patent, it risks giving manufacturers carte blanche to decide who can repair their products. And customers will pay the price.