I've just noticed this a week or so ago also. I tuned my EVO VI(premium) for some easy drifting a while back, and even have a replay of it on Deep Forest raceway. A few days later, I buy the car, and tune it up at my friend's house just for kicks. I get to the tuning menu, and there was no LSD option to be found. the AYC is still there, but u can't uncheck it or anything. You can buy the LSD, instal it and everything, but u can't change the settings. The latest update might something to do with this?