I can't see any door hinge support at all in your picture. This is a must. Your hinge support area needs to be properly located and strong. The dimensions on the following pic are approximately close and are from the red chassis. The body will then be positioned where it will be permanently attached (later) and securely fastened (screwed/bolted). The reason is that once the door is attached and positioned, you will only be able to make minor adjustments when the body is permanently attached. Most all of the mechanical work, wiring, trunk lid hinges, and engine cover hinges and latches etc. have to be done also prior to bonding the body.