Rubber Seal Maintenance - T-Tops and Sunroofs (Page 1/1) hnthomps NOV 21, 03:56 PM Someone was asking me about seal treatments for the t-tops and sunroofs to help prevent leakage. I promised some info on a German seal treatment that I have used successfully for a number of years but cannot locate the original thread. That leads to this post. The product name is: Gummi Pflege Stift Nelson Skybax NOV 21, 07:20 PM Mixed feelings about that product for older seals, because its not silicone based and silicone is one of the best things you can use on older rubber seals, because it replenishes what has been lost over time. Personally I think gummi-pflege-stift is a good product but better suited for newer cars with newer seals and many newer German car fanatics use use it.