LAC: Best vinyl protectant/conditioner?

[David]

As some of you know, I have "Trophy" Recaro seats in my CGT. Well, the passenger side on has developed a 1 inch crack on the thiegh bolster. I plan on using one of those vinyl repair kits on it, but want to keep it from happening again. So, what's the consensus on the best conditioner/protectant for use on black vinyl?

Pic of the seats in question: http://members.cox.net/duandcc_forums/Seats1.jpg

Dave
87.5 CGT 
SE Virginia