From the official NFS website:
"After a few weeks of quiet since E3 we're pleased to reveal a new game mode for Need for Speed SHIFT: Drifting. In the last few years the sport has rocketed in popularity to point where there are large, successful tournaments around the world. When it came time to add it to SHIFT we wanted to ensure the mode was treated with the same degree of accuracy as the rest of the game so we worked closely with Team Falken driver and World Champion Vaughn Gittin JR. Initially the plan was for Vaughn to play the game a few times and give some feedback but he ended up spending more than 100 hours with the team to make sure the Drift experience was as close to real-life as possible.
The team have worked exceptionally hard to ensure the mode replicated the true driving sensation of Drifting and created the same immersive experience as the rest of the racing in SHIFT - just check out the detail inside Vaughn's Mustang if you want more detail of this. While you could already expect the physics to be as realistic as possible, particular praise should go to the car team who've managed to re-create some classic Drift cars into the game.
Designing and coding a drift mode has always been a very tricky experience particularly when trying to make it accessible for new gamers and hardcore gamers alike so the design team spent a lot of time working to make sure the mode is as hard (or as easy) as you want it to be. For new gamers an Amateur setting teaches the basic of Drifting and then slowly ups the skill level until they can complete against the best."
There is also a video at this link: http://www.needforspeed.com/portal/site/nfs/news/details/?contentId=6927c90107162210VgnVCM1000006017780aRCRD