Utilize the input text as a context reference, choose the right relationship between Buick and Detroit from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

And the Cascada convertible, which Buick unveiled at the 2015 Detroit Auto Show, will continue to be built in Europe when the luxury brand introduces it to American consumers next year.

Answer: headquarters_location