As to scratched/neglected windshields - I wonder if those kits for renewing plastic car headlamp lenses would work on a GW windshield? Maybe a kit like these would work?
http://www.amazon.com/3M-39014-Lens-Renewal-Kit/dp/B002UJ13QO/ref=sr_1_2?s=gateway&ie=UTF8&qid=1284806129&sr=8-2
http://www.amazon.com/3M-Headlight-Lens-Restoration-System/dp/B001AIZ5HY/ref=sr_1_1?s=gateway&ie=UTF8&qid=1284806129&sr=8-1
http://www.meguiarsdirect.com/detail/MEG+G1900
A friend used the Meguiars kit on his car and I could not believe the difference.
Rob
http://www.amazon.com/3M-39014-Lens-Renewal-Kit/dp/B002UJ13QO/ref=sr_1_2?s=gateway&ie=UTF8&qid=1284806129&sr=8-2
http://www.amazon.com/3M-Headlight-Lens-Restoration-System/dp/B001AIZ5HY/ref=sr_1_1?s=gateway&ie=UTF8&qid=1284806129&sr=8-1
http://www.meguiarsdirect.com/detail/MEG+G1900
A friend used the Meguiars kit on his car and I could not believe the difference.
Rob