some tips.
the less the editing, the better. some tend to go overkill and the shots end up looking too "shopped or manufactured".
be mindful of where the sun is at, and what time of day you are shooting. i tend to base the time i shoot on the color of car i'm shooting, and the body lines.
for example. just the slight change in angle, possibly the sun and your iso settings really made the second shot pop in body line detail:
high noon tends to bleed out color, the lines you're looking to accentuate and specifically for swirls on paint, the high noon will highlight it.
focus on shooting during the golden hours, usually sunrise or just before sunset.
if possible, keep your backdrops as simplistic as possible. the crazier they get, the more it'll pull a viewers eyes away from the main subject. position yourself while being mindful of what's going on in the background
the lighting in this needs a small adjustment so the paint isn't bled out, but the foreground is interesting enough without pulling the eyes away too much
as compared to this shot. where you have the collection of the sidewalk, outside object shadows, trees along the upper wall w/ poles & wires.
poles and wires can add a nice touch if you position yourself to give off a sense of symmetry. personally i tend to look for backdrops that have nice clean lines or geometric shapes. for the viewer it may be different, but for myself, i tend to feel more relaxed with simple lines, if that makes sense, something like this i guess:
i can see you're working on composition and framing your shots. they look great, keep it up. practice more and more. and i guarantee a few months down the road, your recent shots will look much better than your first few runs.