Afternoon James,
Go with your Wife's instinct... I have not heard of the product you mentioned. To remove scratches i use Fenwicks window polish and www.fenwicks.net to clean the windows have a look on Towsures website as Autoglym to a window cleaner which can be used on Caravan windows, ensure you use a lynt free duster or try Blue Diamonds Acrylic Glass Cleaner.
Hope this helps.
Cheers
Rob.