Try out 303 Aerospace products. They work well on the weatherstripping in the door shuts. Also, I use Black Wow on plastics to bring them back to life, but I don't think it's made for rubber. Try doing a search on
http://www.Autopia.org or searching products at
http://www.autogeek.net 303 is SPF 40 and will keep all your vinyl and seals like new if you use it from the beginning.