There's a whole bus sub-culture out there of modelers who do this. Most of them are HO or O scale, but they really get in to the bus modeling with full interiors, interior lighting, turn signals, brake lights, automatic doors announcement voice and etc. Most of them are R/C though. There have been videos posted for the bus rodeos they hold with the R/C buses at the hobby shops.
But the one or two I saw that took the cake was a model builder from Saitama where the bus had full instrument lights and a working LED destination board (I believe that model was in the 1/24 area in Kesei colors). I haven't been able to find the video for that one again.