If I set the raytracing quality to ultra or extreme a number of visual bugs appear on certain cars.
The BMW 2002 Turbo rear window develops a bizarre non-reflective strip:
Cars that have decals on windows that go away when painting them will show reflections of the decals that are no longer there. As an example, the painted Hoonigan Bel Air:
All of these issues go away when turning ray tracing quality to High or lower