Friends K&N (HD-0818) center broke out last Wed. during ride down from Brentwood with stock 2010 Air Cleaner Cover installed. Vibration and weight made it break off, but he caught with his leg and saved it. Purchased another K&N and installed a 29153-07 Smooth Air Cleaner Cover. Better fit and a lot less weight. Also put a little foam between the end of the K&N and A/C cover to absorb extra vibration. My K&N also broke out with my stock CVO cover, but found it cracking before it fell off. I installed a new K&N with an Arlen Ness Stage 1 Billet Smooth Chrome Cover on the end of mine. Filter is exposed so i'll need to get a sock, but I like the look and it does not touch my leg. My local shop is getting me a replacement for the broken K&N. Seems to be a weakness in the K&N filter construction. Have seen the other K&N filters come with a gasket to go between filter and cover to take up the slack/space. Wish they made one for the HD-0818. Think I am going to have a larger washer welded/tacked to the new one.