There are a couple of things I'd like to comment on.
The crop is not helping the image be presented in the best way. Was the background, where the hay bales are, really nasty? Is that why it was cropped out? If not it needs more room at the top.
The angle is not too interesting. I would suggest giving this more interest by standing more towards the leading front fender, make it look longer.
Because the light is just a little flat a bit more contrast would help.
Possibly a conversion to sepia or some other duotone would also add interest.
Unless there was some reason for cutting this picture down so low, I would've given this beauty a little more head room. It seems unnaturally tight on top.
This shot has potential. There is something missing. I like the rustic feel. Maybe you should have included some of the backround to give a little more of a story to the picture.
I really like this shot, but I think I'd like it even better if it wasn't cropped so close to the vehicle, seems a little tight on top. It is an interesting vehicle though.