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The 650S GT3 has a large carbon splitter up front as part of the factory aero package. It appears to be an integrated part of the one piece floor which means mega bucks to replace if you smash it. You can see the large hood vents. We are surprised that the airflow from the forward heat exchangers to the hood vents is not managed better. The air seems to simply dump into the trunk area then go out the vents. There are some air directors in the hood itself but a sealed duct would be better. Less drag and more front downforce could be had with sealed and shaped ducting. 
The front leading edge of the splitter is beveled upwards from the bottom. This helps reduce pitch sensitivity. We believe this is different from the factory splitter which has a blunt front edge. The car was rumored to suffer from pitch sensitivity on America's bumpy tracks and street circuits during the 2014 season and perhaps this is a refinement to reduce that sensitivity.
These side canards are not part of the factory GT3 bodywork and we believe they were added by the team to improve front and overall downforce. The side canards create some downforce and generate strong side vortices that help seal the sides of the car from air curling off of the top. This enhances the function of the rear diffuser.
Being mid engine means that with the compact Xtrac transaxle the rear diffuser can be quite large. There is no downforce eating differential hump in the center of the diffuser because the Xtrac has the diff in front of the gear cluster for this reason. The carbon diffuser has 8 vortex generating strakes to help the airflow stay attached to its underside over a wider range of speeds.
This diffuser extension is probably another add on by the team as it is not part of the factory aero package. 
The side mirrors make a considerable contribution to a car's aero performance where they can contribute as much as 15% of a cars total drag! The team has done some development here as these are not big, hanging in space factory GT3 mirrors. The door mirrors are much smaller than the factory parts and have vents for driver fresh air in them. A cool idea, no pun intended. The factory GT3 bodywork was developed with some CFD work but nothing has been published about physical testing so perhaps teams can easily improve on the aero.
