During the "restoration of the dome" sequence near the end of the film in which Safety Dance is playing, a dwarf dressed in medieval attire is following the group. This is a direct reference to the original music video for Safety Dance, which features a dwarf in those same clothes.
Henry Gibson starred in The Blues Brothers in which the final scenes of the film had SWAT team members yelling "HUT HUT HUT" as they were moving into position. The same can be seen and heard with SWAT officers near the end of this movie, almost as if it's an indirect reference to The Blues Brothers movie.
Near the beginning of the "safety Dance"/rebuilding the dome sequence, part of the desert area is shown and there are several party goers still sleeping on the ground. This is several days after they re-closed the dome, and these people are never seen again in the movie.
Bud: I propose that we plant these seeds and I know what your thinkin' "Illegal! Illegal!" but the value of purple sticky punch goes way beyond just tokin' it!