Hertz Rental Car commercial in the film
I always liked the running gag throughout the film about Jack Lemmon's ad agency repeatedly trying to film the famous "Let Hertz Put You In The Driver's Seat" TV commercial.
This famous commercial, in which a man, seemingly suspended in mid-air in a seated, arms-out driving position, was magically floated down into a driverless convertible running on the road was well-known in its time, and an early TV "special effects" triumph. At the time, there was a big public "how did they do that?" buzz about it.