Sorry guys, but this is nowhere near pro. I'll focus on the good points first so it doesn't sound harsh - the Colour was a nice choice, something different and fits nicely with the bosozoku theme - also nice stance on the rims. However there are things holding you back. The reflections have absolutely no colour from the surroundings in them, theyre just different variations of lime green. This would be acceptable in a showroom background but not outdoors. The reflections are blurry on pretty much everything, the rear wheel is very very small, smaller than it should be, and the windows have a cyan tint to them that seems to come from absolutely nowhere
I'm not knocking the style of brushing here, but i think you'd get a lot more positive comments if you fit the BG with the brushing style too. It's like having a toon/vexel in a photo background, it just doesn't work. If you want to go down the brushing route, take a look at a lot of reference photo's to see how reflections actually work, pay attention to the colour of reflections and how they fit the shape of the car, where they come from, their intensity etc. Thats the best way to become better at brushing, and of course practice. Start by brushing smaller parts on the car such as a couple of small vents etc. Work your way up instead of jumping in at the deep end
