Why on Earth was the idea of a car program in the most car-crazy nation canned? I don't know. But I do have a few ideas on how it might be made to work. (Please bear in mind that I, like the entire planet except a few people, never saw the pilot of Top Gear US, though I did read a few forum posts from people claiming to have been in the audience.)
First, one has to bear in mind that at its core Top Gear is a talk and variety show along the lines of The Tonight Show, only with cars instead of ostensible social and political satire. Both try to engage with their audiences through humor, and there is a pretty fair reliance on interview segments.
Second, the temptation is going to be to have Top Gear US' co-hosts be big enough names to draw a crowd. That won't mean squat if the hosts don't have the kind of chemistry that Top Gear GB's co-presenters have. A good portion of the enjoyment I get from watching Top Gear is watching three guys "cocking about and arguing," to quote Clarkson. It isn't just about reviewing cars; it's about three guys who love cars sharing their passion for the subject... and insulting each other's tastes while engaging in ludicrous challenges. Incidentally, Colin Fleming wrote a really great article on this chemistry for Slate, which should sell all but the most foolish non-believers on the premise of the show.
I grant you, this is TV: egos abound. But Top Gear is supposed to be three guys who are charming and funny first and foremost, and celebrities second. Finding people who are both (e.g. Seinfeld, Leno) would be preferable, but if you make it funny I believe they will come. And they should be able to share the spotlight... or at least pretend they can on camera.
So let's move on to the 300 ib gorilla and his cousin the elephant over there in the corner of the room: sponsors. Automakers are the biggest advertisers on TV, even in the current environment, and a show about cars would be a logical fit for advertising dollars. But what makes you actually listen to what the presenters on Top Gear GB say is that it's a BBC program, so the lack of ad money means that the only bias the presenters have toward cars is their own, and even then they sometimes eat their words. And yes, NBC did say for the Top Gear US pilot that the hosts could say what they wanted about cars, but if the show had actually gotten off the ground that probably would have started to change in the editing room. And the Stig means that cars make laps at top speed, regardless of who makes the cars... we hope. Plus he makes for an excellent fourth cast member.
Excluding sponsors via ad revenue makes this a very difficult show to be profitable, but there's an obvious choice: HBO, Showtime, or other subscriber networks. This works well since they make money off of DVD sales and subscriptions more than ad sales, and a typical season for one of their shows is only 13 episodes or so, which fits with the rough length of a Top Gear series (though I admit they generally have two series per year).
Speaking of seasons, where to shoot? The obvious choice is California, of course, but obvious is boring. Also, it's hard to get those long freeway glamour shots on the Top Gear car vs. train/plane/Robocop-on-a-unicorn challenges when the cars are stuck in bumper-to-bumper traffic for all day. And the advantage of having a 13-episode season that films and airs during the spring/summer/early fall is that you can get beautiful shots of the northeast without having to deal with winter. Or you can go for the other obvious choices that are Texas and Florida, though I would argue having actual seasons happening around the cars might make for nice scenery when camera crews are setting up those near-pornographic shots of all the exotica.
As for costs, I must concede that I doubt this would be a budget show to film. Top Gear GB's first few series were pretty narrowly budgeted, and while they were fun the show didn't really hit its stride until its fifth series. This doesn't mean a limitless budget is in order, however: manufacturers will readily supply press cars for most vehicles. As for the hyper-exoctica that's already been sold out, look more for Top Gear's strategy when they wanted to test an Enzo: beg, beg, beg, beg and do some heavily tongue-in-cheek promoting (if you watch the clip this actually makes sense in the context of what I've written previously in this piece). The camera work will have to be top-notch though, and that won't be cheap. Neither for that matter, will some of their challenges (though not all, of course).
But hey, this can't be as ludicrous as what they were spending on salaries for The Sopranos by the time it went off the air. And this would be much, much more fun.
