I don't have the 800gs, but the 12gs. I just installed the Desierto 3 on mine and it came with the plastic nuts on the windscreen. I did have 3 bolts with "squared" necks that didn't fit properly. I did give TT a call and they immediately (same day) sent the new hardware. The customer service at TT is top notch, even though the instructions suck and the hardware is not always as exact as you'd expect, considering the price they charge for this fairing!
"I think itís fair to say ó with no scientific evidence ó that deathbed wishes rarely include, 'If only I had put another twenty hours a week in at the office!