Ya, factory mopar rotors for minivans were the worst.... chunks missing out of the backside while under warranty. Showed them to the zone manager and of course, no warranty on brakes its a wear item, chunks missing is a normal wear item I guess. I buy new bendix brand, and bendix pads within a year same thing, chunks missing. I then bought $13 with my commercial discount china rotors, and new free warranty bendix pads from advance and no more issues. Those rotors made it thru the bendix pads, had advance ceramics put on without turning and are on the van still at 200,000 miles, 150,000 on those rotors. Same story on tons of cars back when I did this for side money to support my car habit, good to hear it is still true.