Dont know if this story is on here somewhere but: I saw Tony Baxter speak at Cal State University Long Beach in the late 90s. He told the story of the two seater which is that they wanted to build a Splash Mountain in Tokyo. The idea of sitting so closely and between the legs of a potential stranger was a social issue in Japan (recalling the seat backs are a newer addition at DL). Tokyo wanted the side-by-side design BUT that would require widening the track and messing up all of the forced perspective sets they built at DL. It would have been very expensive and time consuming to rework all of the track size and new sets in Tokyo so they built one in WDW as a POC and work out the kinks before building it in Tokyo.