the material on the ball in kintuX's post looks like flimsy plastic to me
anyway, I added to it the windows and you can see in my image, which is just the viewport with render on. Are you saying the windows were dark because of casting shadows? Not sure where in the pic the windows casting shadows affect is what I'm trying to say
also I added an area light, you can see where in the pic. It washes out some detail and shadow on the road, but brightens the car. Not sure if a point light or something else would be better
yup, 3 secs denoised viewport render tends to look 'plasticky'
and black interior in your case is most likely caused by single-sided (glass (light ray refracts only once) which "Architectural" glass avoids altogether (it's just reflective)
Yes when the glass is casting shadows you have darker results. If the archi glass doesn't look nice you can revert back to the first glass material you were using.
Try rotating the light(play with the power and size of the light) to the opposite direction from the car hitting the barrier in order to behave like a bounce light, something like this: