Whynumber of spokes of automobile wheel are odd in number?

engineers from mavic have proved that odd number of spokes are more aerodynamic. apparently it has something to do w/ even spokes creating turbulence. I'm not sure of the exact benefits from a structural standpoint though. but based on the fact that it takes 3 points to define a plane, a 4th just becomes an unnecessary extra weight, drag, free space real estate.. etc etc blah blah..

read up on it.