Every new car sold in America wears a sticker almost nobody reads. It lists exactly how much of that vehicle was built domestically, expressed as a single percentage. This past weekend, that obscure sticker became Elon Musk’s favorite talking point. What Musk didn’t mention is that the number on it is filled out by the automakers themselves, estimated months before the model year even starts, rounded to the nearest five points, and blended with a country most people don’t consider part of “America” at all: Canada.
The exchange started, as these things do now, on X. Podcast host Katie Miller shared a Wall Street Journal report about Ford and General Motors shifting production back to the United States, adding that “every Tesla sold in the United States is assembled in the United States.” Musk jumped in to one-up her: “More than assembled. The parts are overwhelmingly made in America too.” A day later he went further, quoting Cybertruck lead engineer Wes Morrill’s claim that Tesla vehicles carry an 84% domestic content score against 63% for Ford. “Tesla cars sold in America are the most made in America of any cars,” Musk wrote.
That 84% figure is real, in the sense that it comes from an actual federal disclosure requirement. It is also close to meaningless as a purity test, and understanding why says more about how little regulators actually verify than it does about who builds the best truck.
The number both men were quoting traces back to the American Automobile Labeling Act, a 1994 law that requires automakers to disclose the U.S. and Canadian parts content of every passenger vehicle they sell, along with the country of origin for the engine and transmission. It sounds rigorous. It isn’t quite. Per NHTSA’s own explanation of the rule, manufacturers calculate the percentage themselves, on a “carline” basis rather than per vehicle, before the model year even begins, using projected sales mixes and supplier quotes. The final number gets rounded to the nearest 5 percent and never separates U.S. content from Canadian content, because the law was written to treat both as the same country of origin.
Cars.com, which has published its own American-Made Index using this same underlying data for 21 years, describes that blending as a flaw built into the law, and notes it can’t be reverse-engineered from the public filings. In other words, when Musk says Tesla’s parts are 84% American, what he actually means is 84% American-or-Canadian, self-reported, and locked in before a single one of this year’s Model Ys rolled off the line.
Here’s the detail that got lost in the back-and-forth: the man who supplied Musk’s statistic builds a truck that doesn’t have to report one. Wes Morrill is Cybertruck’s lead engineer, and the Cybertruck’s gross vehicle weight rating pushes it into a class the American Automobile Labeling Act simply exempts. Anything above 8,500 pounds falls outside the EPA’s light-duty classification, which is also why the Cybertruck skips fuel economy labels and the more detailed assembly disclosures that come with them, according to Cars.com’s published index methodology. Tesla’s most talked-about vehicle of the past two years has never once had to wear the sticker its own engineer used to win an argument.
The irony compounds. In January, Tesla discontinued the Model S and Model X, the two vehicles that had ranked in the American-Made Index’s top 10 every year since Tesla started participating in 2020. That single decision, combined with Volkswagen pulling its Tennessee-built ID.4, helped shrink this year’s qualifying list from 99 vehicles to 86. Tesla’s actual footprint of U.S.-built nameplates got smaller in 2026, even as its CEO spent the week bragging about how American the two models still standing happen to be.
None of this is happening in a vacuum. Commerce Secretary Howard Lutnick spent the same weekend crediting the administration’s auto tariffs with returning “thousands” of manufacturing jobs to the U.S., pointing to Ford’s decision to move Lincoln production out of China. Ford CEO Jim Farley has confirmed the Lincoln Nautilus, currently imported from China, is absorbing a 52.5% tariff, and that domestic Nautilus production won’t start until 2030. That gap between the tariff announcement and the actual factory opening is the real story sitting underneath the Twitter fight: reshoring a supply chain takes years, but claiming credit for it takes a weekend.
That mismatch shows up across this year’s American-Made Index too. The Jeep Grand Cherokee jumped 66 spots after Stellantis raised its U.S./Canadian parts content by 14 points. The Lexus TX 350 climbed 34 spots once Toyota moved its engine and transmission sourcing entirely onshore. Those are real, physical supply-chain changes; they take retooled plants and renegotiated supplier contracts, not tweets. The top 10 vehicles on this year’s index now average 70% domestic content, the highest since the index’s methodology was standardized in 2020. Whatever tariffs are doing, they are genuinely reshaping where parts get made. It’s just happening slower, and more unevenly, than the men taking credit for it want you to believe.
This was never really a contest about which badge deserves to say Made in America. It’s a reminder that the label itself was built for a slower, simpler trade war than the one it’s now being used to fight. A sticker designed in 1994 to help a shopper compare a Honda to a Buick is now being cited by a trillionaire’s Twitter account and a cabinet secretary’s press conference as proof of an entirely different argument. The next time an automaker, or its CEO, cites a domestic content percentage like it’s a verified fact, remember: it’s a projection, it’s rounded, it counts a foreign country as home soil, and the company grading its own homework wrote the rules for the test.