Looks good mate!
However i do see some faults here and there.
* - The brushing is good, and you seem to have understood the basics.
But in some places it lacks details, like the rear for example.
The rear fender is very flat, and doesnt look very good, especially with that blur.
* - The Selections on the car isnt very good, as you can see around your fenders, it is very jaggy, and the same at some places overall on the car. These small things really drag the quality of a chop down amazingly much, so always take time when making your selections. Remember to always use pentool aswell, even if its a bit hard to master, once you master it it makes everything 100x easier
* - Some more details which could have been improved:
1. The rims, they are very lowres. And once again that blur you did at the rear doesnt look that good, as the rear rim is totally blured out.
2. The front grille mesh, it looks abit flat, and a bit unreal. Mostly cause it so repetetive to use it on such big areas, i think it would look better if you fitted an ic in the front, and two ic pipes behind the mesh on the sides.
3. The car seems to be quite off, its tilting alot to the right.
4. The shadow isnt that good either, looks to unreal.
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* - How to fix the shadow :
I will tell you how i make my shadows

1. Make a selection for the "hard" shadow, which is the strong shadow that comes directly under the car mostly. Once you made the selection create a new layer --> then fill it with black.
2. Take the blur tool and blur the outer edges of this shadow.
3. Make another selection that is suitable for a "cast" shadow, which is basically the same but goes further out from the car, and isn't as dark. After you've made the selection once again you create a new layer.
Place the new layer under the "dark" layer --> fill the selection with black colour, now reduce the opacity of this layer to about 10 - 30% ( it really depends alot on how the lightning etc. is on the picture. )
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I hope my comments will help you
Peace,
Alex "nibs" sjögren.