You should probably make the rear wheel arch similar to the front one. The rear one seems to be made from a circle with less sides. How about making the wheel arches a little bigger, then extruding it a little to make it look more like the wheel arch on Filipe's picture? If you do that, you should probably add the little flat area which could be seen there.
You should consider moving the bottom corners of the front windscreen downwards a little more to make it follow the curvature of the cowl.
Otherwise it seems like a good base model to work from.