Mass produced product is the answer. Needs to adapt to whatever option someone may want. IMHO, Corbin needs to make it work for the customer and not their production line. I agree the flap looks like chit if you don't have or want a backrest. I own the complete Corbin package for seating on my 9. I have the front/rear and rear backrest. While I'm happy with th Corbin seats. I do think that their customer service has a lot to be desired and their pricing on new products is outrageous.