Here is another idea, it might have been done before, but not on this show, at by this point, everything on tv now, has been done before at one point.
Genious Not At Work - Tired of being labeled a computer nerd, Wade quits Team Possible, to presue other interest, and be a normal kid. Can Kim and Ron survive without him? Can they convence Wade to comeback? Who will take his place?
Would this include the back story as to how Wade joined Team Possible in the first place? That's something that I've always been curious about, but has not been answered so far.