VW was initially disappointed that its factories in the southern US weren’t unionized. All their German factories are.

I’ll see if I can find the article, I think it was road and track many years ago.

Edit: the previous failed votes were blamed on Tennessee politicians including Bob Corker.

In 2014 VW was reported as:

Volkswagen did not oppose the U.A.W. partly because its officials were eager to create a German-style works council, a committee of managers and blue-collar and white-collar workers who develop factory policies, on issues like work schedules and vacations. Volkswagen, which has unions and works councils at virtually all of its 105 other plants worldwide, views such councils as crucial for improving morale and cooperation and increasing productivity.

Source