Thanks King - Curious - have you used any of the Gummi Plege products on your BMW? He used some here -
http://www.autopia.org/forum/589734-post39.html
#1 - refreshing me that petroleum distillates are the harmful portion, not really silicone. Here's and excerpt of what I'm seeing online " For the weather-stripping, use a non-solvent based, silicone lubricant or grease. Mequiars Vinyl and Rubber Cleaner and Conditioner is one example and GM Goodwrench Dielectric Silicone Grease (part no. 12345579) is another. If you choose to use the silicone grease, apply a small amount to the weather-stripping using your fingers. Wipe off any excess with a clean rag."
Now for #2 - skeptical of the "water-based silicone" - Impossible I say... but anyways the problem here is the ability to last. My 303 just won't stand up to extended exposure to the elements.