How's this nationalism? It's about keeping money within the United States. Just "buy local" on a bigger scale. US parts means US manufacturing jobs which are few and far between these days.
Rail is heavily used for shipping vehicles from manufacturers that put out large numbers, making it pretty economical and environmentally sensible to ship from Canada, Mexico, and many US states.
I'm unable to understand how it's not nationalism. It's literally a league table of the most national made vehicles. If you want to argue whether it's pointless or not, that can be up for debate. But things designed to make you feel national pride are nationalism.
And just to drive it home. Pun intended. Here's the first two definitions from the American Heritage Dictionary
Devotion, especially excessive or undiscriminating devotion, to the interests or culture of a particular nation-state.
The belief that nations will benefit from acting independently rather than collectively, emphasizing national rather than international goals.
Nationalism yes, but "Pointless nationalism"? They left off a key word in that.
from rdyoung's comment
it’s better for the environment to
Pointlessly shipping material from one side of the world to the other, then back isn't good for the environment. It may be good for the economy, but a few nations economy isn't the whole picture.