Leakless is the sponsor of Claude Scruggs, a racecar who was in the first race at the beginning of Cars. His number is 52. And on the back of the car, it says: "leak less - adult drip pans". During the race, he crashes with race car Todd Marcus. Claude has a forklift named Stacy and a crew chief named Earl Filter.
Before Cars 3, Claude retires and is replaced by Brian Spark. After the Los Angeles 500, Brian was fired and was replaced by a next gen who was severely damaged after the the accident in the Florida 500.
It is actually a dripp pan brand to prevent old cars from leakino.