If you are planning on attending Bubs and running in open class (not partial streamlined) make sure you read the addendum to the seat rule:
Any aerodynamic aid at the rear of the motorcycle (including the riders seat section), shall not extend past the most rearward edge of the rear tire, shall not be higher than 4 inches above the lowest section of the seat base, nor extend below the seat base by more than 1 inch.
It is going to make about 75% of all bikes illegal by the way they are interpreting this rule. basically almost all bikes with a stock seat will be considered illegal under this rule as they are measuring from the bottom of the seat (not where you sit but the literal bottom of the seat at its lowest point) to the top of your tail section and almost all bikes nowadays have an angle to their seat or the passengers section sits higher. My Buell Blast with a stock seat and tail section is illegal under this rule.