Great job!
I was playing with a composite earlier today and I was not happy with my results. So by sheer coincidence, I was just watching this
VIDEO TUTORIAL on how to blend images together!!
I feel that the man and car in your composite could benefit from balancing/blending the luminosity and saturation. I don't think there's much color to blend, but the luminosity and saturation could use some tweaking so they look more like they belong. The man and car came from a strong dark background and was added to a light more colorful background.