The 2013 Cadillac ATS is off its media embargo, and not a minute too soon. Since late June, we've been waiting to spill all we know about the new compact sport sedan, and frankly, we've been expecting that some other outlet would break the mutually agreed-upon curfew.

It's a small miracle that didn't happen, since there's a huge story here--that Cadillac has nailed the BMW formula for handling that's eluded all the competition. It's elbowed aside the Infiniti G37 as the challenger most capable of displacing the 3-Series as the luxury segment's benchmark four-door. It's picked the most difficult lock in the industry.

Yes. It's that good.

No single thing spells the demise of the 3-Series' iron grip. The ATS just accumulates win after win. There's exterior styling that's admittedly a watered-down version of the aggressive Art & Science theme that rocked Cadillac back into existence in the early 2000s. It's clearly Cadillac, but in silhouette it's a ringer for the BMW as well as the Benz. The ATS' cabin clocks them both, with rich materials and a cohesive looks dominated by CUE, the iPad-like controller that lets go of myriad knobs and buttons and replaces them with a glowing, haptic touchscreen. It frames the Cadillac argument neatly: it's BMW, but beyond.

Without the right running gear, in fine tune, the ATS would fall as flat on its face as the Catera--the Caddy that zagged right into automotive history's footnotes, complete with a laugh track. Consider that passage erased. The ATS is brilliantly composed, with electric power steering and a multi-link suspension that know each other intimately. It's clear from only a mile or two of driving, that this is the most tossable, responsive Cadillac ever built--and that's before you tap the 272 horsepower of the mainstream version's 2.0-liter turbo four, or the throaty 321 hp of the available 3.6-liter V-6. (If you're choosing the base 202-hp 2.5-liter four, you're not even reading this.)

 

Best in rear-drive though all-wheel drive is an option, the ATS makes automatic transmissions a forgivable decision, with cool-touch magnesium paddle shift controls and shifts almost as quick as those from a dual-clutch transmission. We'll stick with the manual--it comes only with the turbo four--and its light shift action, though the clutch uptake could be smoother. We'd also stick with the ATS' Performance trim level; it doesn't get the Premium model's Magnetic Ride Control, but it's so low on body roll and high on grip from 18-inch run-flats to begin with, the driver-adjustable MRC system seems like a plush indulgence. In any case, you're looking at a very crisp-handling sport sedan with adjustable steering and throttle feel, exceptional straight-ahead tracking, and 0-60 mph times in the mid-5-second range.

Cadillac's cabin shines with CUE's ambient glow, and it's functional and handsome in a way that only Audi does better in this niche. But while the front seats are truly great for a day's worth of hard driving, the back seats are one of the ATS' few Achilles' heels. It has less legroom in back than all its competitors. Given its target market, it's probably fine, since it's likely to be used as a four-door coupe most of the time. The trunk's tiny too, though a couple of golf bags can be crammed inside.

Awash in high-tech safety options, including a seat that vibrates when you wander out of your lane, the ATS is the second Caddy to carry CUE. We've explained it at length in our full review, but in shorthand, CUE makes the German roller controllers look goofy, and shows how an extra year of development time lets engineers render everything more clearly than in Ford's fussy MyLincoln Touch system. We experienced a glitch or two with CUE, but it's no doubt the best of the mass-market infotainment controllers--and it bundles HD radio, Bluetooth streaming, SD card reader and USB ports, voice commands, and a handy bin tucked behind its flat-panel display.

The 3-Series has roundhoused all challengers over the years, but cracks formed a few years ago when Infiniti introduced the G35. Since then, the replacement cycle has grown worrisome for Munich. The Audi A4's only gotten better, as has the C Class. The Lexus IS is due for replacement, and there's also a new Infiniti G in the pipeline.

But it's the clear and present danger that should worry BMW the most. The 2013 Cadillac ATS is here. And it's the best driver's car the brand has ever built, shy of a letter V or two. Any bets on how long it takes to add one of those to its badge?

There's much, much more on the latest Caddy sports sedan. For more information on performance, styling, features, safety, and pricing, see our full review of the 2013 Cadillac ATS.