You did a pretty good job.
Everything I write below should start by "IMHO" ...
A : The rainbow effect feels weird.
B : An empty plate feels just as weird as what was there before... You should remove the whole plate..
C : I'd like to get at least a little bit of sky reflection in the windshield... Something that makes it fit a bit more with the side windows
D : This highlights feels weird.
E : There's something weird with the ground... This late in the afternoon, the ground should be way more contrasty I think...
Red marks : Just a few visual annoyances I'd get rid of.
I also think you should push the highlights toward a warmer tone... The side of the cars is great, but the top feels like it's lit by something else than a warm late afternoon sky.
Hope this helps.
JK.