Well if it's matte paint that you're going for it's not looking too shabby
Certainly very clean, tidy work for now, but watch out for the little light lines that have appeared around the edge of your selections on places like the bonnet vent etc
I also think you need to make the split lines/ door lines a little stronger and clearer
If you're planning on leaving it on this backdrop too, it might be nice to try and mod it with some slight lighting and scenery changes to really make it your own image
But keep going - looks promising, I hope to see more soon