With the wonky base materials lighting removed from vehicles, they're no longer over-dark in overcast skies or shadows when applying the ambient occlusion texture to them. So, they get detailed AO darkening, but still look natural in the scene. Until I figured out the screwy materials lighting was darkening stuff, I was just applying the AO texture to the AO lighting, which washed it out and made vehicles over-bright in shadows. The AO texture needed to get applied to the base coat (color) of the vehicle. But, doing so made them over-dark in overcast skies and shadows. So, with the materials lighting removed, we now have AO texture applied and looking proper.
With the wonky base materials lighting removed from vehicles, they're no longer over-dark in overcast skies or shadows when applying the ambient occlusion texture to them. So, they get detailed AO darkening, but still look natural in the scene. Until I figured out the screwy materials lighting was darkening stuff, I was just applying the AO texture to the AO lighting, which washed it out and made vehicles over-bright in shadows. The AO texture needed to get applied to the base coat (color) of the vehicle. But, doing so made them over-dark in overcast skies and shadows. So, with the materials lighting removed, we now have AO texture applied and looking proper.