I mostly got the bug guard for looks, but I have noticed more DOA's on the guard than on the windshield though. There really hasn't been any messy to clean up on the windshield, so when I stop & think about it, I guess it really does work. Its pretty sturdy too, feels nice and solid on the Ridge.
I also have put 2 coats of Scotchguard on the interior, 1 coat of NuFinish on the paint, and 1 coat of RainX (love that stuff!)on the windshield.