Stop trying to classify it, just leave it be.
You definitely wouldn't know it to look at it, but a lot of the underpinnings of the Dodge Challenger are German. They date back to a time when Mercedes was “partnered” with Chrysler, and the platform comes from the old E-Class. That makes it a weird thing to call a muscle car, but the styling makes it weird to call it anything else. As the following video concludes, it's more GT car than anything else, a comfy two-door ideally suited for long trips.
Philosophically speaking, it has a lot in common with some other big coupes like the Bentley Continental GT, albeit in a very different price range. But that might be too philosophical to get into here.