I have a 23 RST 6.2 with the performance package. While on a road trip at about 4900 miles it started making a whining almost grinding noise and the transmission was struggling to shift. As long as I was driving at a steady speed with no hills it seemed OK. Then started making the noise at start up too. I was traveling home to AR from FL. So it's now at a dealer in Alabama. Not getting much help from the dealer or Chevy customer service. Had to pay out of pocket for a rental to get home with hopes that chevy will reimburse me for travel expenses when the car is repaired. The dealer in AL said they didn't have a loaner. Trying to get chevy to get it to my local dealer for repair now, as they said they can get me a loaner. Anyone have any luck with similar situations?