I've used it for years on my car windows at speeds well below .82 and it does work well.
We even put it onto the Tower windows at EDI a few years ago. The Manager asked Rain-X what it would cost to apply it. They said £2000!!! <img src="eek.gif" border="0">
I bought a bottle with money from petty cash and the window cleaner applied it for nothing!
Its about £6 a bottle in the UK but only $3.50 at WalMart. Go figure!