Indeed I did cross post to FB after posting here as seems it gets different folks.
I'll summarize the responses here for the record. Things disappear quickly on FB!
Ron I would love to hear your comments on these questions.
One commenter believed GC would last "forever" if you keep topping it off with HS.
Others disagreed with this view.
I questioned what causes a coating to break down, is it the bond to the paint or external wear, or both?
Others questioned if HS will crosslink with GC seeing they are related products.
Also Ron, how does the gloss and slickness of HS compare to OCW?
Can you also confirm the ph resistance range of GC and HS?
I know Yvan would also say Opti-coat is resistant to ph 0 - 14, not sure if the same if true of GC.
I know so many questions!