Saman Yaghmai-Aledavoud's mother once saw her first owned car in the street about twenty years after she sold it. Yaghmai was with her at the time, and remembered the incident after writing the script.
The old car used in the movie is a 1973 Alfa Romeo GTV.
The signatures in the trunk belong to Saman Yaghmai-Aledavoud and Mike Toofer. The date is May 27, 1984, which is Yaghmai's birthday.
Art Wright, the sound mixer, became interested in working on "The Old Car," since he restores old cars as a hobby and had seen a signature in the trunk of one of his cars. He kept that signature and never painted over it.