I don't know if it's appropriate to say that this one is over-photoshopped. It's so heavily stylized that it's going well beyond the reaches of simple photo-editing and moving into photo-art territory. That Miata actually looks like it was painted, which is a neat effect.
It's not my personal style either, but it's an interesting piece. My only real suggestion would be to try and stylize the car's surroundings so the edit work looks a little more cohesive. The car stands out too much at this point and looks unnatural in its settings, despite the overall unnatural look (which I presume was a goal).