And that's the reason Top Gear USA fails for most of us. The UK version was already a popular show in the USA, so when you try to duplicate the formula here in the USA, it's just not going to work. It's like taking the cast of Seinfeld and one day replacing them with a new cast. Pretty awkward. Instead, they should have just done a spinoff of it if they wanted to import the show to the USA.
Shows that have been imported to the USA that have worked in the past have been so because they weren't already airing here for a long time.
ps - I know Seinfeld doesn't still air, but I don't watch TV shows that much and couldn't think of a current TV show to name, ha ha. But you get the point.