What a great tut, I just loved modeling the spitfure. When dealing with the wings, you dont have to follow the video to a tea. There are much better ways to deal with a few topics presented in the video's. Your first objective is to combine 2 surfaces while keeping geometry clean. The video suggest using a boolean if I remember right. I used the bridge tool. There is also a ton of edge work, this edge work surves one purpose which is to maintain a shape when subdivided. You can very easy do the spitfire a a low resolution model to define its poly shape then when your poly model is complete .. go back & do the edge work, you need 3 edges for each edge to control smoothing. Also you may want to forget about the edge work, instead when nyou convert to subs, add full & part creases to selected edges which does not change the resolution of the poly mesh & does a much better job.