The Sport 6MT for the G37 provides certain features lacking in the sequential transmission models. A viscous limited-slip differential, sport-tuned steering, and high-performance rims, tires and brakes are all standard equipment on the Sport 6MT. All the racing transmission upgrades in Gran Turismo are manual shift transmissions. I imagine owners of sequential transmission G37's are not showing up for track day racing. Why bother with the sequential transmission for racing purposes? Unless of course you own a sequentially shifted G37 and want to pretend it's a race transmission.