Volvo's flagship sedan was introduced for the 1999 model year and got a mildly freshened appearance for 2004. The front fascia was reworked, and the grille surround was re-profiled for a gentler transition to the bodyside cladding. Fog lamps were added, and the grille contained a square-mesh pattern.

More important to buyers in the Snow Belt, the 2004 lineup gained an available all-wheel-drive version. The system works automatically, transferring power to the rear wheels only when the front tires have lost traction.

Volvo's Four-C active chassis became optional for front-wheel-drive sedans in 2005. A new Sport package for 2.5T models in 2005 included sport seats and 17-inch Interceptor alloy wheels.

For 2006, the T6 and T6 Premier editions are no longer offered, leaving only 2.5T and 2.5T AWD models with more standard equipment. Premium and Sport option packages have been dropped, but their contents — including leather seating surfaces, a power glass moonroof, genuine wood inlays, a wood-trimmed steering wheel, a power passenger seat, 17-inch wheels and watch dial instrumentation — are now standard.

Volvo says a new Instant Traction all-wheel-drive system for the 2006 2.5T AWD sedan "instantly delivers up to 50 percent more torque to the rear axle only when needed."