Shortly after getting the new truck I had eventually used the seat conditioner. Afterwards I noticed a dark dime size spot on the tan leather seats just under the drives left thigh. I wiped it away, but next time I had used the air seat feature it would reappear. This went on all summer. When it got cooler I no longer used this feature and the spot did not reappear until recently as the weather finally got warmer. It was suggested I made the spot, but I could accept that except it only reappears when I run the air cooler in seat. No diagnosis yet.