Start/finish filling is a nice to have. Most of us should use only 1 to 2 gallons.
A sticker say "Hypermiling Student Driver" that we can put on the rear bumper may help the hypermiler and other drivers.
A map of the course to be available a few days before the rally will be great. For those have a GPS navigator, they can enter the course in to the GPS before the rally and the GPS will guide them through the course. This will be easier than reading the map looking for signs while hypermiling the same time.