I like the angle at which you photographed the car and the barn behind it. but the lens flare and how the front of the car is a different color than the rest is distracting and don't help the photo. Also the sky does not look natural at all.
The sky looks unnatural to me also. The direction of the lens flare doesn't seem to coincide with the angle of the sun.. I like the composition..Did you desaturate the barn? It also doesn't look natural. If you did, then I would suggest to desaturate the sky as well and leave just the car in color.. I would increase the saturation of the car somewhat. I'd be curious to what you have done with it prior to posting.
All I did was change the sky, add the lensflare and take out some wires that were hanging down in the picture. I like your idea about desaturating the sky and barn. Maybe I will try that. I wasn't going for a realistic look for this picture, I was trying for something different. The car looked so sad there but you could tell that it had been very beautiful at one time.