I only ordered Two. They are flimsy and I didn't think they would hold up On the freeway and such but so far so good. And no more whistle

 

Found this old topic but I decided to post because there is a good solution to reduce the sound of the lightbars.

So there is company Z-roadz, and they make noise canceling deflectors for their long lightbars. They are bigger than rubber strips and attach with screws, so they will not come off on the freeway.

Zroadz® Z330050S - Noise Cancelling Wind Diffuser for 50" LED Light Bar

They are confirmed to fit on the Zroadz lightbars, but we can't guarantee a proper fitment with the lightbars made by other brands, as we haven't tested them yet.

If this particular item doesn't work for your Cherokee, you can DIY something similar

 

I've heard that it's the ends that Whistle if you cut out a piece of plastic and glue or silicone them in the ends it will stop Whistling .

 

hmm

$100 deflector or 90 cents of rtv

hard to choose