The U.S. car industry is synonymous with the city. Could the industry have arisen elsewhere in the U.S.?
AIUI, the reason Detroit became the hub was because of the number of local wagon-builders, which raises the obvious question why they found the area so attractive.
The car business, like the bicycle business before it (& on which a lot of carbuilding tech relied), needed skilled technicians & sophisticated manufacturing methods which wouldn't (necessarily) be available everywhere. It also needed a fair amount of $$ to get started & survive.
So, what other options might there be? Chicago, central to trade? Boston? New York? New Orleans, where thousands of wagons were built? Concord, where the famed stagecoaches were built? (Every one you've ever seen in a movie is a Concord design, & they were very numerous, once.) South Bend, Indiana (home of Studebaker), where hundreds of thousands of wagons were built? New Bedford, Mass (based on whalers' shipwrights & $$)?
And does it depend on when the car business begins? Would (frex) a steam car industry originate somewhere an IC-engine industry wouldn't?
(FYI, I'm asking this in pre-1900, because both Olds & Duryea were around then.)