Well you should listen to the advise we all give you..

Begin small! try to make some small changes at first and when you've got that working you can go and make concepts like you're doing now.

But most important of all, we give you advise and I suggest you listen to them if you want to improve.

Try to listen what people said, or else you will be doing the same mistakes over again and again. And as time passes, no one will comment on your wip again.

i just don't get it

I'll go ahead and make racecars first.

You mean those nascars again?

A little bit lesser tone then them, not as much modifications.

2012 Hyundai Azera BTCC:

Base:


WIP1:

2012 Hyundai Azera BTCC WIP2:

The spoiler is off.. o.O fix that..

-The angle of the car is side on, so the spoilers should as well.
-The background is obviously moving, so maybe just make the wheels spin. so go to filter> blur > radial Blur
Or find new rims which are already spinning/ in motion.

As for colors not matching, try to lasso tool around the area you want to change colors.
then go to image > adjustment > hue/saturation and just play around.

Liking the color though