Here is an Idea I had and tried it.  I cut the sides off the stock Air Filter Cover and opened it up to free breathing.  I have not done a lot of testing on it yet.  Only Rode it about 20 miles like this so far.  Amazingly my backfire disappeared, the small popping when down shifting.  Also throttle response improved drasticly.  Acceleration and low speed cruising 5 to 10mph improved.  Hoping to do some testing this weekend as we are Hitting 70's again.

But basically it is the same as adding the open air cleaner to the older, non computer driven engines.  As you can tell I ride an 04 Sporty with Carb not EFI.  Not sure how it would work on a FI.

I bought a complete kit, nuts, back, front, filter, on line so if it failed I would have the original cover to go back on.  Found it for $50.

Have not completed it yet, still needs to be painted, and the cut back plate installed, but that is about it.

And I think it looks kind of cool with the K&N showing through.

I am guessing this would work on any Carbed bike.  FI would have to be retuned.  

What if you get caught in the rain..?
..or maybe I'm missing something.....

We just drilled 1" holes in back and bottom side of cover.  Looks great, no cost, no rain intake & performance increase as well.  Either way,..good luck.

Rain would be my question too. A soaked air filter will not breath very well.

Working on a clip in cover for the front and top. Plastic that will just pop in and cover it up. Leaving the bottom and back half closed. I got so much going on had to put it on hold for a while but when I get it completed I will post a photo of it....

Have an oldschool air cleaner cover over my K&N that is cut out towards the front.  Been caught in the rain many times and it never skipped a beat..  Have 88" EFI...