The 2013 Cadillac ATS has some serious challenges ahead of it. Mid-life crisis convertible aside, there's no car segment so fraught with identity issues as the compact sport sedan. So far, the BMW 3-Series has been the "I've made it" model to beat, a heady Teutonic mixture of performance, prestige and affordability, but Cadillac is hoping the smallest model in its range can light an American torch to rival it. The specter of the baby Beemer looms large over each aspect of the ATS, but that's not to say the German icon has things all its own way. We caught up with Cadillac at a 2013 ATS preview to see whether the all-new car was truly as "world-class" as promised.