Charles..I get it right at the dealership..its the concentrate not the pre mixed....here is a link to it
Window Cleaning Products - Auto Glass Cleaner : GM Goodwrench
also does under AC Delco
Appearance | Vehicle Care Products | Parts Information | ACDelco
where it says select drop it down and select optikleen
if you look at the MSDS sheets on 90% of glass cleaners..its just alc and water and a little surfacant...so why pay 4.95 for a can of that when 4.00 gives you 2-3 gallons....
hope this helps you Charles.....
AL