My airbox had the two sides held together with screws. I did have it replaced under warranty at the 600 mile mark (the old one was cracked). Maybe I got an uprated airbox? Was the airbox different on the sprint sports from some of the other 900 engines? I know these were supposed to be replaced as a unit (airbox and filter), but mine has held up to yearly removal, separation and K&N filter cleaning.The K&N won't make the disposable airbox last any longer, though, and cotton gauze filters don't filter very well compared to foam.