05's still had all carbon wings (VIII's). 06 (IX's) have the plastic sides. and some 05's also have peeling issues. 2 of my friends have 05's and they are peeling.

 

Well if the middle section is thicker, that is usually better. The reason I say this? I actually BROKE my carbon fiber wing on my IX this past weekend. Here is the link to the write up and some of the pics!! I don't recommend doing what I did. Broken CF Center on wing