Honestly? I can't see the difference BEFORE and AFTER - the car looks very dark . . . put up a the original PNG so we can tell - yeah? This, IMO, is NOT a good enough example to allow me to make a comment.
Eh? I can't see it myself. Perhaps others will see it?
What I see in the rendered image is more detail - not the trees through the car but the trees reflected in the windows/paintwork of the car.
I note you have the preview set to "Preview(Auto)" which will reduce the resolution of the preview window (deliberately so that playback is less jerk). Try setting it to "Best (Full)" and then compare.