they aren't some random show just copying topgear. this is an officially licensed top gear show. They already have had top gear australia for years now.

a friend of mine runs a blog and got a sneak preview at the first three episodes. Looks promising. Here's the link, but there are some spoilers so don't read if you don't want to be surprised.
Top Gear US: First Three Episodes Reviewed: SPOILER ALERT! : RawAutos.com :: Appealing to the enthusiast in us all