I went to a showing of Bill and Ted's Excellent Adventure and Bill and Ted's Bogus Journey last night at the Aero Theater in Santa Monica, and between the movies there was a panel with a bunch of the cast and producer Scott Kroopf.
Alex Winter (Bill) said that they are working on a third film, although it sounds like it's been tough getting it actually started. The premise is that Bill and Ted have fucked up and Wyld Stallyns are not a famous, influential band. The powers that be in the future come back and they have 10 hours to make an amazing song or it will never happen.
The studio wanted a younger Rufus, so Scott Kroopf talked to Charlie Sheen about the part. Even he knew that wasn't a good idea (the role was played by George Carlin).
Alex and Keanu went on repeated auditions for the parts over months. Amy Stoch (Missy) had to audition six times.
Diane Franklin went in to audition for Joan of Arc because she had just done a French accent for Better Off Dead, then was asked to read for the role of Princess Joanna.
It came close to never being released due to studio financial issues, and they were spooked by the release of Back to the Future. Alex said he and Keanu joked before filming the first scene with Socrates that nobody would ever see it. It was almost released directly to HBO. Scott convinced the studio to test it and audiences loved it.
Keanu was supposed to be a surprise guest on the panel but canceled two hours before because he was sick. However there was a young guy in the audience who cos-played Ted who looked and sounded great!
Other than a few establishing shots, nothing was filmed in California. It was shot in Phoenix and Rome.
Left to right: Moderator, Alex Winter (Bill), Diane Franklin (Princess Joanna), Kimberly Kates (Princess Elizabeth), Amy Stoch (Missy), Arturo Gill (Station, Bill and Ted's Bogus Journey), Scott Kroopf (producer).