In A Moment

The entire conversation in the car was recorded in real time; Eva Craw recording her side of the phone call with one microphone, while Gabriel Garcia recorded his side on another microphone and talked to her through an ear-piece as not to drown out his own audio with her voice echoing throughout the car. The two sound recordings were later mixed together in editing.

On a close-up of the phone in the car, you can see that the sound of the call was running through headphones; not Bluetooth as portrayed in the film.

The credits are completely silent with no soundtrack or sound effects heard at all.