Running tripple, msaa, shadow split on, NV 1080, win10-64 There is a Halo effect around the wheels/tires caused by disappearing pixels of the contact shadows. It looks like the tire geometry is rendered into depth buffer slightly bigger than the visible wheel geometry. Then when ground shadows are drawn a few of those z pixels block them. There must be a small mismatch in geometry or transformations during zpass that causes a tiny visible gap (2-3 pixels). Only saw the gap on left side of tires.
here is a screenshot, it's actually not just tires, I noticed it on the whipers in the cockpit as well (Daytona prototypes), essentially things that seem to move a lot. Almost as if the previous frame's matrix is used in the depth pass or some other mismatch of shade and depth pass.