Sika Corporation 106711 Self Lev Sealant
Sikaflex, from the Sika corporation, is a combination polyurethane and silicone sealant, making it one of the few paintable silicone sealants around. This sealant provides superior adhesion on almost all surfaces, even without a primer. The cured sealant retains flexibility and is waterproof, but it also isn't designed to withstand engine oil. Back when I was engineering in the bus plant, this is the primary sealant we used on the bus bodies, to take care of openings where water might enter. Once dried, it paints well and will not come off. That makes it perfect for auto body applications, even though it was actually designed for construction.