Questions about Windblocker/Windscreen

[Jeph]

The screen makes a world of difference. One day I was driving on the highway without it and I noticed in the rearview mirror my ears flapping in the wind! Trust me, it's hard to look cool with that goin' on!

There should be some clips on the inside of the roll bars as seen in the attached pic.

I see them on eBay a lot, they're pretty expensive anywhere you go. Are they worth it? Well, my car came with the screen, but if it blew off or got stolen, I'd definately replace it!