GM gave all the hourly employees a $12,750 bonus check this year because of company profits.

Actually. No one else will.

UAW was unable to unionize non-big 3 factories in the US.

Past performance is not a guarantee of future results.

There's a huge wave of increased support for labor in the US right now. It's definitely not a good idea to bet on any particular area remaining un-unionized.

You’re not getting it.

There is zero chance non-us car factories unionize. There is nothing stopping them from closing the factory and moving internationally. The same isn’t true for the big 3.

Sure there is: whatever reasons led them to build factories in the US in the first place.

And for, say, German automakers, they already have unionized workforces outside the US.

This whole narrative of "we cannot possibly try to improve anything for our people, because any time we do the wealthy overlords will move their business/money/etc overseas" is demonstrably bullshit, and always has been. It doesn't hold up for raising taxes on the wealthy, it doesn't hold up for unionization, and it won't hold up for whatever the next thing people like you try to use it to argue against will be.

Thank you!

No one will pay them a fair wage because there will no plants for them to work in. The US manufacturers will simply ramp up offshoring of entire vehicles to China. The new Lincoln SUV is an entirely in house design from Changan motors soup to nuts. You can fully expect this to become common for US brands.