I can't find it now, but I was reading some postings the other week about cleaning/restoring s2k tops.
Quite a few people recommended 303 products (link below)
In particular, the 303 Aerospace Protectant and Convertible Top Cleaner?
I've only just bought an s2k myself so have limited knowledge but thought I'd pass on other peoples recommendations.
Hope this helps?
http://www.303products.com/tech/inde...category_id=70