Change Lower Hemisphere Color in skylight to a somewhat light grey. It might make the lines disappear, though they can still remain there, just not visible. If that’s the case though, then it probably has something to do with distance field shadowing and something in the skylight. Another thing to attempt is increase AO radius, resulting in surfaces further apart to affect each other in shadowing. The idea I have there is getting a more uniform shadow level with AO, potentially filling in those gaps of the car shadow’s bands.
Cubemap resolution of the skylight is rather low. At 256, it would result in far more accurate reflections and shadowing too, I bet…or 512.
Increase the number of skylight bounces to 2 or 3, and decrease intensity scale a bit (down to 1.5 at the most I think) to offset the change and dim it back to original brightness.
One last one, decrease AO intensity in the post process by at least .1 or .2. Then use the Advanced dropdown below that to access and modify the Exponent or Contrast properties. Increase those to re-intensify the AO shadowing while maintaining the light levels near heavily affected AO areas. It might help reduce the shadow banding for the animated car too.