Powers: Pretty good process, there...
If one wants to try a less abrasive/rigorous approach on less abraded covers,
I rec'd "303": I've used it for years on m'cycle windshields and helmet shields.
Will not cure deep scratches, but for an initial "clearing", it is remarkable stuff,
imo. It does require some hunting to find it, outside the bigger metro areas.
GL,md
http://www.303products.com/main.php?infopage=home