While accelerating hard from an intersection today the rear tires spun and hopped. When I let off the gas there was a strange "loud ticking" sound coming from the drive line somewhere. It only occurs when the car is in gear and I'm off the accelerator. If I put it in neutral and coast there is no noise. There is also no noise when in gear and moving. Any ideas? Any help or ideas appreciated. BTW I was coming home from watching and autocross and the testosterone was on full. Lessson learned, or maybe not, it was still fun spinning the tires.