Changes mainly concern aerodynamics, with the adoption of a new, completely redesigned rear diffuser and front splitter and the introduction of a completely flat underbody to increase downforce on the front of the car and balance the large rear spoiler. (autonationdrive.com)
The exterior is also changed, with a Model X style front fascia and redesigned rear diffuser. (evo.co.uk)
It does this by incorporating more AMG design language which includes giving the front bumper a new A-wing design, a lip spoiler on the trunk, and a redesigned rear diffuser. (loebermotors.com)