I installed a Quaife differential in the early spring, got an ECU tune at Kleemann, and invested in wider tires as the only modifications in my owner time, but I have never drag raced it. I though use manual gear mode a lot and downshift/brake often with the gears (its difficult not to, as this is the easiest way to get pops and cracks from the Exhaust). How I discovered the fault: I noticed a rattling/rumbling noise in idle, shortly after a trip with some spirited highway driving with good topspeed, and after that the car was a little difficult to get rolling after stops, and it also went up in rpm before shifting, almost as when a clutch on a manuel car is slipping. Shortly after I stopped by my mechanic, and he has now discovered that the flexplate was shattered almost like a broken window pane, and that my converter was shot. Should the car not be able to be used a little rough without breaking something in the driveline ?