Post-Apocalyptic Bus Concept

I saw this image online, and, in loving it so much, decided to start work on a 3D model of it. I don't own the image, and am only using it as reference. Here's the website for the image:
http://digital-art-gallery.com/picture/big/561

 Here's my model, roughed out:

Took about 2 hours to get to this point, working back and forth from the one image.