I have a 3 month old Mazda 6 with a very light gray leather interior. I have already conditioned the seats once overall with Wolfgang leather conditioner, and the driver seat alone four times. This may seem like a lot, but I want to keep ahead of the dirt on that driver seat, as I drive a lot on business. I absolutely love the Wolfgang conditioner - it actually seems to have softened up the leather to a rich suppleness without a greasy feel - plus the leather smell of the conditioner adds that something extra to the interior. I have already received numerous comments on the richness of the interior. I don't think you can over-condition the leather, providing you don't go hog wild and apply a lot at a time. Each time, I apply a minimal amount, work it in a little, and buff it dry within a few minutes, and I am very pleased with the results. I've used other conditioners in the past, but the results I've gotten with Wolfgang are by far the best I've ever had.