I have a 2015 Stingray with the standard wheels. My LF tire started losing pressure. Thought I had a nail. Took it to the tire store for repair, and they said the wheel was cracked. Since I haven't hit anything I took it to the dealer for warranty repair. Dealer says GM denied the warranty claim because there was a scratch on the inside of the wheel, and the crack could be physical damage. The tire is fine. Since I know I haven't hit anything, and you can tell by looking at the wheel that it hasn't suffered an impact great enough to damage it, I think it was a defective wheel. A new wheel is $550. I'd like to appeal. Any advice?