The taxi driver was laughing so much at the effort required to get four people in his taxi on Saturday night, two of whom were wearing "very large dresses", that no fee was charged, Ms Mannion said.
The voluminous dresses, worn by Ms Mannion and her spouse Eva Gluyas, were made by the couple for the movie-themed party attended by about 40 people.
Film-buff Ms Mannion, a speech and language therapist, wore an Elizabethan dress similar to that worn by Gwyneth Paltrow in Shakespeare in Love.
Product design consultant Eva dwarfed this with her version of the gown worn by Deborah Kerr in The King and I featuring a 2.2m diameter crinoline.
Ms Mannion said the construction of that garment featured easily opened fasteners which allowed Ms Gluyas to remove the dress so she could use the toilet.
The design did not make sitting easy, but fortunately the celebration at the Otago Polytechnic restaurant Technique was a buffet occasion.
Later, the free taxi took the couple to The Moon Bar in St Andrews St, where the limited space for Ms Gluyas' dress caused further hilarity.
Prospective guests were sent a copy of 50 of Ms Mannion's favourite films, in no particular order, and those attending were asked to choose.
Once a couple made a choice that film was ruled out for the others.
Among the films represented were Priscilla, Queen of the Desert, Edward Scissorhands, The Addams Family, Memoir of a Geisha, Alice in Wonderland, Pirates of the Caribbean, Pulp Fiction and The Matrix.
Among those on the list but not chosen was The Full Monty and The Rocky Horror Picture Show.
Some films which had been chosen by prospective guests who were then unable to attend included Cabaret, Zorro, Walk the Line and Star Wars.
Ms Mannion said she was delighted with the evening and the effort the guests had gone to, but thought she would hold low-key birthdays for the next few years.
