Tesla just beat out Ford as the most American-made car for the first time ever

• Tesla's Model 3 sedan topped Ford's Mustang in the Cars.com American-Made Index this year.
• It's the first time in 16 years that Tesla has topped the list.
• The American-Made Index ranks American cars by how much of the car and its parts are made in the US.

In a ranking of dozens of American cars, Tesla took the top spot over rivals from American giants like Ford and Jeep - but not for the reasons you might think.

The Cars.com American-Made Index, now in its 16th year, ranks dozens of American-made cars to determine which is the most "made in America" of all. It takes five primary factors into account: final assembly location, origin of parts, origin of engines, origin of transmissions, and manufacturing workforce.

To that end, Tesla's Fremont, California-made Model 3 sedan took the top spot - the first time ever for Tesla.

Ford's Mustang, made in Flat Rock, Michigan, took the second spot, while Tesla's Model Y SUV rounded out the third spot.

Ford and Tesla have come into increasingly close competition lately, with Ford's wildly successful Mustang Mach-E directly taking on Tesla in electric car sales. Ford's first all-electric Mustang made a big enough splash when it launched earlier this year that it immediately cut Tesla's market share in the electric car market by over 10%.

Despite the competition, Tesla CEO Elon Musk and Ford CEO Jim Farley appear to share a mutual appreciation of each other.

"Tesla & Ford are the only American carmakers not to have gone bankrupt out of 1000's of car startups. Prototypes are easy, production is hard & being cash flow positive is excruciating," Musk tweeted in March. "Respect," Farley said in response.

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