Ah, Carbon. I rented it a couple days ago and am quite enjoying it. I'm in the last part of career mode, going with exotics exclusively up to this point. I got quite far with the Alfa Brera alone but it sucks for drifting. I've got a Cayman S, Mazda RX-7, and a Lotus Elise thats tweaked to the nines. It sucks that you can only get so many cars in career, apparently most of the cars can only be used in quick race mode. F that, I say.
The town is much more interesting to race in than in MW, and the gameplay and physics feel somewhat improved. Also, the canyon races are fantastic, although I'm stuck on the one against the Lamborghini Murcielago, It's a tough one and my poor Elise either gets bullied off the road, or I keep hitting the walls trying to keep up with it. So, I'm just going to save up a bunch of money and get a Carrera GT