The Hey Hey YouTube channel just uploaded their 1992 show recorded in the Showstage at Movie World.

https://youtu.be/NGv60ERN75A?si=MTcdWqKRWNlKZgO3

Looking at the audience shots, that has to have held at least 2000 people in the seats (~30 rows, with ~30 people in the right-most side section, and extrapolating from there). I am sure that someone here has better information about the capacity than that.

Imagine being able to take 2000 people out of the other queues for 45-60 minutes by staging a 30-minute show 3 times a day. They really need to bring back an audience sponge like that.

The full episode used to be there but it's gone now. This clip shows great footage of the Looney Tune River Ride.

 

The episode aired the Saturday night before Movie World's grand opening the following Monday. This ad was shown during the commercial breaks.

https://youtu.be/KKZj25tYFfA

For anyone unaware, The Showstage (main show shooting location) is currently the WB Showcase. The floor area of Showcase is where the stage used to be, and the black drapes that surround the movie props (on the right side as you enter) are all hiding the grandstand seating behind. 

Showstage used to be open air at the rear, but was enclosed later in the park's life and "fully" climate controlled.