Eric Powers, a friend and former GreenHybrid.com moderator, organizes this annual event:
Green Drive Expo - Madison
I have only gone once for 'booth duty' but enjoyed the crowd and meeting folks and enjoyed the drive up and back.
As I drove north, the calves got smaller and the corn taller. I drove up with 175/65R14s on the front and 175/70R14s on the rear. Before driving back, I swapped front and back and found the larger diameter tires improved straight-line stability, a lot.
GreenDriveExpo does have an 'open' car driving contest the day before but I have no idea about the scoring. Fortunately, the driving contest is not sponsored by any one company or dealership so it should be a hoot for those who want to compete.
When I was there, I order this electric bicycle:
http://hiwaay.net/~bzwilson/prius/pri_ebike_010.jpg
I had to build my own charger but it still runs and is good for errands.
Bob Wilson