Imported automobile brands, like Hyundai, Toyota, and Subaru use metric-sized bolts, while American-made automobiles, like Ford, generally use SAE-sized bolts. This gets more complicated when certain parts of a car are manufactured in the United States while others are imported.
Although this makes it tricky to know which sized sockets to buy, it’s more likely that you’ll need metric-sized sockets. While it’s always safest to get a set with both (and it’s hard to find a set that doesn’t include both), more and more cars come with metric sockets these days.