I own a 2018 Limited. It has had very minor problems. I'm at 55k miles now. I took the vehicle to the dealership for an oil change and new tires. I asked them to check the brakes as everything is original. They said the rears had 4mm left and front 8mm. They recommended I do the rear pads and rotors either this time or next oil change. I chose this time. I get a call today that they can't finish my rear brakes because both calipers are leaking brake fluid and the calipers need replaced for $600 additional. Did I get taken? They said they could only find this issue once the brakes were off. Also, is that typical for the rear brakes to wear that much faster than the front brakes?