When Cadillac introduced its reinvented STS midsize luxury sedan two years ago, it was an acclaimed departure from the more traditionally-inspired, cushy-riding vehicle it replaced. Styling was fresh and rakish, with crisp edges and aggressive stance aimed at winning over the trendy and toned. Agile, rear-drive handling underscored the transition.

With an update expected next year, the STS gets refined performance aspects for 2007 with the inclusion of equipment previously only on the performance "V" series of it autos. The addition of the 6L50 Hydra-Matic six-speed transmission gives a "launch" boost to takeoffs while keeping passing power and quiet smoothness at speed. Sport driving, built into this generation of STS, is enhanced by using the new transmission's clutchless manual mode on equipped models and by choosing "performance" rather than "touring" mode.

That activates GM's Magnetic Ride suspension that uses electro-magnetically charged shocks to instantly firm up support during aggressive maneuvers. With it, any decades-old "Boulevard ride" transgressions are but a faint memory.

Powering up the base model (starting at $43,135) is an all aluminum 3.6L, 254-HP V6 as rear or all-wheel-drive. More grunt and high speed loping power comes from GM's 4.6L Northstar V8, in both drive configurations, that mates with the new six-speed transmission. Best fuel economy is rated at 18 city/27 highway for the V6 with rear drive.

Tech-wise, there's an Easy Key system, Adaptive Remote Start that takes the chill off frosty mornings, Intellibeam, ventilated seats, heated steering wheel, and GM's four-color head up display (HUD) the driver can configure as preferred. Bose sound, including DVD, CD and MP3, pours out of 15 speakers. Bluetooth technology is there for phones. On nav equipped STS models, Caddy adds Turn-by-Turn Navigation to its OnStar safety system, interacting with a remote live attendant. Customized driving directions are downloaded to play through the sound system with no need to stop.

Cadillac takes direct aim at BMW (5 and 7 series), Mercedes-Benz, Lexus, Audi and Jaguar with this generation STS. A 469-HP supercharged Northstar engine in the STS-V model, introduced last year, makes it the most powerful, performance-oriented Cadillac ever built.