when u guys r driving ur Z (auto) and racing someone, do u guys shift when u let go of the gas at high RPM or do u guys just shift it without letting go of the gas??

 

With the autos you're not supposed to let off the gas it will cause a leg it does not hurt the transmission to leave throttle on when shifting it manually.
I feel you're much better off just leaving it in full auto accelerate and don't let off and it will shift right at redline.