Second. Don't post the exact same thing on the forum in 3 separate places. I understand you want info, but spamming the boards with the same question is overkill.
Third. I'm not sure there's anything you can do to prepare your cat. I hope your cat does well with strangers and is highly food oriented, if so, he should do fine. If he's nervous or skittish around strangers, ignores food in public places, etc, the audition could be very nerve-wracking for him. He'll also probably do better if he is fine travelling in a small animal crate, as you'll have to use it to get him to the audition site. How is he on a leash?
Never trust a tall dwarf... he's lying about something.