you have done a good job to pan with the car to get great sense of movement. For me though it needs something more otherwise it is just another picture of a moving car - there isn't an 'angle' or thing that really grabs my attention. Well captured though.
A good pawned photograph where sharpens lies on the head subject the car. By good pans of the moving car are not only the car perfectly sharp but become vaporously the context as a result of which the context is no longer annoying and the context contributes to the feeling of speed.
Personally I the carriage centrally will have placed less and the car Right to less free space has given. This way you the more impression gets that the carriage the picture comes within driven.