However much you want to extend it. In my picture you'd have to print it out and take some measurements off the picture. I don't know how you'd create the exterior body curves, I'd probably consider cutting up a door to start with. On the inside you'll have to patch in the stamped roof section. I think you'd have to cut up along the edge of the door, come across the drip rail and then cut across the roof to do it right. Cut where you can patch in flat metal. Then you come to the new window question...
Lee
