This would be my general thoughts on how to go about it from a conceptual standpoint.
You mentioned you wanted this in Storybook Circus, and one way to do that is converting the Pete's Silly Sideshow into the Mickey's Fun House facade. The facade can either resemble the original Mickey Mad House design, replicate Pete's Silly Sideshow, or be something entirely your creation.
As you enter into the building structure (no longer a tent) you wind through the queue that can introduce you to the 'Mickey's Magical Nights' events - in which the ring leader Mickey and his pals Minnie, Donald, Goofy, and Pluto work with their circus cast and crew to perform acrobatics and stunts. This traveling circus has come to Storybook Circus to put on a show. Their most prized attraction in their traveling circus is the 'Fun House' in which visitors travel in colorfully decorated carriages into a house of zany fun. Odd shaped mirrors, special effects, and much more. While the show is run by Mickey, the circus is owned by Pete, whose presence is felt throughout the queue and attraction.
Throughout the queue could be several props and memorabilia from their tours, which would be a good place to put your license plate idea. Have it line a wall with all sorts of innuendo character names in the letters.
The queue winds around the right side of the building structure, and can hold approximately a 60 minute wait inside the queue, before overloading into Storybook Circus. The ride, with 8 scenes, as you had wanted, would probably clock in around the same time as Peter Pan's Flight (approx 3.5 mins) given space limitations.
You load unto carriages that will take you into the Fun House. The attraction will mostly use basic motion Animatronics along with digital projection technology (2.5D) and other special effects.
Scene 1 - Introduction to Mickey and his pals.
He greets the guests and sends you on your way through the Fun House entrance.
Scene 2 - The Mirror Maze.
Your vehicles meander around odd shaped mirrors as 2.5D projections (tech used in Mickey/Minnie's Runaway Railway) adapts the surroundings to different shaped mirrors and settings as you circle around.
Scene 3 - A Loose Seal!
Donald, performing a stunt with 3 seals (homage to Mickey's Circus) accidentally lets them loose and they crash into a barricade, sending your carriage spinning into the next room.
Scene 4 - A Goofy 'Movie'
You crash into a projection room within the Fun House that is responsible for the special effects throughout the shows. From your crash into the projection room, Goofy, in charge of the special effects, accidentally sets off fireworks in the room and you're dazzled and dodging pyrotechnics as your carriage careens backwards out of the projection room.
Scene 5 - Pete's Surprised Reaction
As the seals break loose, fireworks continue to go off, and your vehicle is careening backwards. Pete grabs a hold of Mickey and tells him that he's finished for all this damage he has caused to the Fun House he owns. Soon you hear the bellow of the seals as they pop in and surprise Pete.
Scene 6 - Midway Madness
While Minnie and Pluto where in charge of the midway games portion of the Fun House, Goofy and Donald's previous mishaps have caused the effects in the Midway section to go crazy, with pop out figures coming out of the walls, moving targets spinning out of control, puffs of air coming from above and below ground, all while your vehicle attempts to make it back to the entrance of the 'Fun' House.
Scene 7 - Mickey's Finest Hour
Approaching the finale, Mickey races ahead along with the other fab five members, as they are being chased by Pete and the seals, and closes off the remained of the Fun House from the guests. In a loud bang of a finale, the carriages regain control, and Mickey breathes a sign of relief.
Scene 8 - Unload
Ragtime jazz circus music begins to play as you approach the exit to the Fun House. You reappear near the load area, disembark and head back through the main queue building structure and to the Big Top Souvenir. However, on the exit path over to the gift shop, there's a meet and greet with circus Mickey and Minnie, held over from the old Pete's Silly Sideshow M&G attraction.
Guests then enter into Big Top Souvenir, and exit back out into Storybook Circus.