Just finished installing the opti-air airbox on my rzr. I got the airbox and clamp from my local fleetpride store for $138 including freight and tax. I made a bracket that goes from the opti air bracket to the stock filter bracket out of some scrap sheet metal using a vise and hammer to make a bend. I then went to pep boys and bought a 3" flexible air duct made by spectre, part number 8741 for $19.99 and a small pcv filter, also made by spectre $10.00. Sorry already threw that box out so i dont have the part number, but you cant miss them. I used the pcv filter for the valve cover breather hose as you can see in the picture. The flex pipe was used to go from the factory air intake duct to the inlet of the opti air without having to modify the factory intake whatsoever. (I cut just the amount of flexpipe that I needed and shaped it with my hands into an oval and fought it into the hole. It was kind of a whore but it will go in without any trimming.) There was no modification to the rzr itself, so if needed I can return it back to stock without any evidence that the opti-air was ever there. Here are some pictures, let me know what you think. There is actually enough material in the package for the flex pipe to do 2 opti-air installs as there are 2 couplers and only one is needed.