I did the AI experience a few weeks ago and just a heads up........
Get there about 30 mins before opening where they will be auditioning by the normal queue's and you can therefore move onto the producers stage before the park opens.
Once you have auditioned make sure you get your free fastpasses. One for each member in your party good for 1 ride.
Put aside at least your entire morning for it and then your evening if you get through to the finals.
Have a great time, it was one of the best things I've ever done