2014-15 cruze diesel uses the 292mm rear rotorsFor anyone still having this issue with uneven wear on the rear disk brakes, I've had this issue twice. It's looking to be the caliper pin that has the rubber, GM PN 13584090. The first time this happened the brakes on the rear passenger side were fine, but the driver's side wore down to the metal. (around 50k miles) I replaced both side, pads and rotors and made sure to clean out the caliper pins well, and lubricate them with the special disk brake caliper lubricant designed for high temperatures.
Now I've had the issue now a second time (around 70k miles) The driver's rear pads are completely gone and again the passenger side is fine. Despite having lubricated the caliper pin, one of the caliper pins seems to be binding again. It's almost as if the rubber on the pin has expanded and is causing it to bind. Only one caliper pin has rubber. The one with rubber attaches to the low-frequency noise damper. As an experiment, I'm going to file down the rubber to provide additional clearance for the caliper lube. The caliper itself does not appear to be binding up anywhere.
Also worth mentioning there appear to be two different rear rotors. Mine is 265mm, not 295mm.
Caliper pin with rubber: GM PN 13584090
Low-frequency noise damper: GM PN 13343688
Stock GM Pictures can be found here