Just thinking about this, apart from a catastrophic manufacturing fault that would show itself before taking the car to a track, would not any engine issues following some track time likely to be the owner's fault? i.e Strapping it before it was warmed up, over revving the engine etc. It might be possible that Nissan has gotten sick of people claiming stuff on warranty when they're really just incapable of driving properly and/or properly maintaining the car.
Faster, faster, faster, until the thrill of speed overcomes the fear of death...
– Hunter Thompson