vomit comet n. any form of transportation on which riders are (jocularly) said to become nauseated or seasick, such as an airplane that simulates zero-gravity conditions or a bus that transports late-night revelers. (source: Double-Tongued Dictionary)
Further reading
The German phrase Der Bus hält an jeder Milchkanne literally translates as “The bus stops at every milk can,” and refers to a bus that stops at every little out-of-the-way town. This is part of a complete episode. Transcript of “Stopping at Every...
The Oldsmobile car was introduced in 1897, and shortly thereafter people began using the term oatsmobile or hay-burning oatsmobile to mean “horse.” OATS is also an acronym for Older Adult Transportation System. This is part of a complete episode...
When I entered into the construction industry in 1974 a vomet comet was widely used to refer to the lunch wagon truck appearing before work, break and at lunch.
I did find one other use of the term used in that way, but the incidence didn’t seem common enough to warrant inclusion.