Visually the rear lights will tell the biggest difference. The rest of the changes are more mechanic. Expect Direct fuel injection which will like with the face lifted Cayenne give the 997 a healty increase in power. PDK is also rumored to be one of the future options for the facelifted 997. Then there are other things going on like with the big plastic object behind the front air intake? Unlike most manufacturers Porsche's facelifts are all about making the car better and faster.