OK, sorry I can't be more help. I would have gone for a vert in a flash and may well have ended up with one if I hadn't become interested in a Z06. Love the top down, but I do love the feel of the Z.
There are a number of sources of info on convertible top care and products to use. Here are a few:
http://www.detailcity.com/convertible-top-care.html
http://www.autogeek.net/contopcleanp.html
I might have a few more links for you if you don't find what you're looking for
..........Tom
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Cor·vette : [ kôr-vt ]n. 1. A fast, lightly armed warship, smaller than a destroyer, often armed for antisubmarine operations.