to me it seems like you have some pseudo-banding or something like that going on in some places. Most notably on the highlight. I'm not too sure how its happening though...
It's because of the damned angles.
Angles like these, and especially on prominently contrasted, thin objects -like the silver lines going all over the car- will inevitably give off the banding feeling. Trying to fix them can be time consuming and often futile, it can sometimes make someone reconsider the whole design, for appearance's sake.
The car does seem in need of polishing, so we may see it being fixed soon, perhaps?
This style is amazing.
I think Mr. Fahrenheit meant the highlight on the car's hood.
Yeah the angles and the hard contrasts, as well as the outlined style seems to cause some problems with banding. I can live with that, to a certain degree since it also shows that it's still pixel art, which is not bad, which is of course no excuse if there is a better approach to solve the problem. However I won't abandon certain angles.
But thinking about how to improve could is an interesting challenge.
I tried to get rid of the dark outlines at all unecessary spots and sharpened the AA here and there.
Maybe really minimal AA would be in general a good idea and just using more AA were I intentionally need it. I have to look at that in detail.
Made it a little darker, still using Greg's colors so no colors added, I think the current version is a little too bright and too yellowish:
Value changes are a really great idea and seem to work much better with the strong chiaroscuro used everywhere else.
I also applied this to other objects as well.
However all your colors were "off", seems that you have the saving problem you already had earlier again.
There were some things bugging me about the car, I made a edit since I don't think I'd be good at explaining it..
I disagree with a lot of points, you destroyed the barrel-formed front of the car and made it really flat. You also destroyed the radiator mascot.
Nonetheless your edit gave me the idea to emphasize some parts with a gold color and overthinking some spots and the shading here and there.
For the car I changed the value, the shading, lots of AA and a bunch of details.
I edited the lantern and the boxes in terms of value.
I also created some bottom tiles and a park bench to enhance the scene a bit.
Scene (WIP2)

Graphics (WIP2)
