There are some issues with both the shadow quality as well as rendering distance from the camera.
See the following screenshots, taken at the highest shadow quality level for the PC:
In screenshot 1, the car's shadow doesn't have the same quality throughout. Observe that above the red line the shadow is fuzzier and below it clearer. If you pan the camera around you'll see that the shadow quality isn't related to how far the shadow is projected from the car, but rather just how close it is from the camera. Your own car's shadow should always have the highest quality enabled, there's no need for such a performance optimization.
In screenshots two and three we can see just how close non baked shadows start to render. The vertical red lines separates the shadow/no shadow areas.
Screenshot 4 has one of the most noticeable shadow rendering effects in game when viewed in motion. The whole highlighted area is fully shadowed only from close up.
In general full shadow details only come very close to the camera and for the PC at least the users should have the option to both increase the quality (for the car shadow) and render distance of shadows.