To make this a viable, profitable enterprize you have to keep it very reasonably priced, easily manufactured, and simple. As soon as you add slots, holes, springs, screws etc etc...costs increase etc....and it gets over priced in conjunction with manufacture and competor price. What you need here is a simple snap on snap off side rail deflector devise devise, most likly plastic composite, although some thin spring steel materials can actually be press fabricated much cheaper than injection molded plastic.....Cost needs to be in the $2.00 area or less and sell for no more than $8.00...Keep in mind you are selling a product that is not really needed by hardly anyone, and is a very limited market.....you need to entice sales because it will work, and it is very REASONABLY PRICED.....best regards Plum