I thought I would toss in my .02 as I just recently attended a live filming for the second season of Top Gear US (free tickets FTW!). While we, the audience, were waiting between segments, they were showing us all of the rough edits of Season 2. The four episodes we watched were SUBSTANTIALLY better than anything the first season did. I won't do too many spoilers, but our episode's "Star in a Small Car" was Bridget Marquadt and she is pretty damn cute IRL, but a terribly slow driver.
Moral of the story is, give it time to work out the kinks. Good chemistry between hosts takes time, and that's crucial to a good show.