This year what we had done was, elect 3 equal team leaders who had experiance of at least one year (ended up being myself, Frank, and Dan) and basically let them decide who would head what. We also elected a secretary (well, I don't remember there ever being more than 1 person wanting the job). Then the 4 of us were the 'executive counsil' which was overseed by the 2 adult leaders to make sure we didn't become too much of a dictatorship.
Team leaders just always end up being the drive team because we pick them by:
1. work done this season/last season
2. experiance driving
3. do they know the game inside and out
4. can they cooperate with the rest of the team
In previous years we had also done individual group leaders such as, mechanical, electrical, design, autocad, animation, programming, and secretarial... But as has been said, thats a little too much organization on a small team like the one I was on. For a small team, 10-20 people, 1 president and then 2 vice presidents, one for mechanical and one for electrical/programming, and then a secretary that also oversees PR and funding should be more than enough.