From Nissannews.com:

Infiniti G35 Sport Sedan

The big news for the 2004 G35 Sport Sedan is the addition, beginning in early December, of the G35 Sedan Leather AWD model. This new model features an advanced all-wheel drive system with an active torque distribution management system with an electro-magnetic clutch (no center differential). The advantage of this system is smooth starts and better traction and maneuverability on snowy roads and minimal compromise of rear-wheel drive performance characteristics on dry roads. Torque distribution front-to-rear is computer controlled and is variable between 0:100 and 50:50 front:rear.

All 2004 G35 Sport Sedans express Infiniti's bold new direction of combining leading-edge design and technology, driver-oriented performance and a high level of luxury. The G35 comes standard with a 260-horsepower 3.5-liter V6, 5-speed automatic transmission with manual shift mode or close-ratio 6-speed manual transmission, 4-wheel independent multi-link suspension and rear-wheel drive.

Enhancements to the 2004 G35 Sport Sedan include:
· New G35 Leather AWD model with ATTESA E-TS all-wheel drive system, including "Snow-Mode" switch which fixes the torque distribution ration at 50:50 to improve performance on slippery roads
·Standard heated outside mirrors on all models 17-inch wheels now standard on all models
·Improved standard 6-disc CD changer (with faster operation)
·Standard Tire Pressure Monitor System
·Standard rear limited-slip differential on Leather 6MT model
·Heated front seats and 4-way power front passenger's seat standard on Leather, Leather 6MT models
·Engine will meet LEV2 standard for emission control (beginning with October production)
·Two new exterior colors - Diamond Graphite, Twilight Blue (previously available)