Canada

Just because I'm a car history guy, I think you have some broken information about Opel.

The company predated Nazi Germany by a long shot as a general equipment manufacturer in the 1800s and was one of the biggest auto producers in the 1920s holding over 25% of the market. They were actually bought by General Motors (not Ford) in 1929.

Where you did get it right is the famous Brandenburg factory was funded partly by the Nazi government and to specifically make the Opel Blitz trucks. Which were at the time just a general work truck in high demand. But soon after GM lost control and the plant was used to exclusively make military trucks for the war. But this is the same for any factory at the time.

A lot of this can be explained by the US political attitude to Germany where they kept up positive diplomatic relationships up until the attacks in the Pacific. The large companies like GM didn't have a direct reason to divest from their ties to Nazi regime, as they weren't really denounced themselves and still an important trading partner. Their investors would have had protests on a change of course. For GM, Opel was a huge success at the time.

Of course cutting ties and divesting would have been the moral thing to do, but capitalism has no morals... Apple doesn't mind making products in China today but sanctions on tech are already changing the course for companies like Nvidia, not without lots of protest by their leaders.

Also yes Henry Ford was idolized by Hitler and Ford didn't mind that one bit.