I do not use the product for the roof of my Porsche Boxster, even though the car is over 10 years old, with daily use of the car, a 2 times Annual application is sufficient. We recommend the cleaning of the roof before the top cleaner offered by Dr. Wack. For the impregnation, you should allow some time because the body and the plastic of the folding windows must / be covered taped, so that these gotten no spray (it can indeed Dr. Wack nothing). But after that you can clearly see in every shower that the water bead up properly from the roof again. So is also easy to recognize when was possibly used to weing of the Preodukt / or bodies have been omitted.
Also highly recommended is the cleaner / polish for Kunsttoff Convertible slices of Dr. Wack!
