Termite I think you might be confusing the ACO "stand" with the ACO grandstand.
You need a grandstand ticket to use the grandstand but I think Peter and Del are referring to the ACO "stand" as in the building, you can get into the ACO building with an ACO wristband and use the showers, screens etc. but you need a grandstand ticket to get into the actual grandstand.
I think that's where the confusion is coming from

(I could of course just be confused myself!)