Honestly man, This is What I'm in school for the best advice that I could give to take this to the next level as a vector piece is as followed: start black and white go around the entire silhouette with the pen tool, then drop in the whites one by one in chunks simplify it. Keep contrast in mind, so with the jacket and the car, if you notice how the car kinda fades into the bounce light of the jacket go in and make either one black or white so it really pushes it (sometimes even separating it with a thicker white gap (or black) really can make it pop. Add some bounce light on the left leg or some light in the grill behind it (continuing the grill would do a fair job) Seperate the face a little more between the glasses and the nose, or let it fall into darkness a bit more and put bounce light on the nose and glasses.
If this threads still alive in the morning and I have some time I'll actually do this all for you (P.s. The color gradiant works pretty well)
