[Whisper1]

This is all new to me and I've had my 2012 since 2014 when I purchased it with 7K miles. Reason I bought the car is after researching a bit I had read that the transmission and rear end were bullet proof. The claim from a GM engineer was that they had made roughly 600 passes down the drag strip without any rear end issue. Way back 14 years ago independent rear ends were notoriously weak so it was supposed to be better than most.
Anyway, I have seen mulitple cars in 2012-2013 make a boatload of passes without issue.
I hear you on the whine. Mine is whisper quiet at 30K miles so I'll keep my fingers crossed. Not an IRS, but I had a Moser 9" in my F body. Took me two tries from the factory as the first unit howled at an ear splitting level. Even the "good" one I recieved still had a fair amount of whine and it also leaked fluid. Local performance shop owner said the Moser could be guaranteed to whine and leak fluid. But, they were durable. Anyway, distressing to hear about yet another parts issue. I just assumed the rear end could be swapped with an aftermarket unit but I'm hearing no? Thanks for diving into this.