redlining your car for short periods of time will hardly do anything to your car (racing, hard acceleration, etc.).
the danger in redlining is DRIVING in the redline. this may cause you to drop your tranny because it is not made to maintain those rpms (8k and above in the gts..except '02) for more than a few seconds at a time.
as stated earlier, the danger is more to your tranny than to your engine but obviously driving your car hard will add extra wear to your engine (although small..every little bit counts). if your an occasional racer, then redling for a couple of seconds trying to land lift will hardly do anything to your car. if your just driving around, it's better just to stay as far away from the redline as possible (less wear = longer life).