The 1928 Porter used in My Mother the Car was not a production car. Real Porter cars had existed. The first was a steam automobile (Boston, Massachusetts, 1900–1901). The second car was a powerful luxury car made (Bridgeport, Connecticut, 1919–1922) made from parts left over from production of Finley R Porter’s FRP. By the 1960s, no examples of either remained.
For the TV show, assistant prop man Kaye Trapp leased the producers a 1924 Ford T-tub hot rod he recently bought from his friend and its builder, Norm Grabowski. Both Grabowski and the car had earlier appeared in the B movie comedy Sex Kittens Go to College (1960).
The 1928 Porter touring car sported diamond-tufted naugahyde upholstery, oversized white tonneau cover, plush black carpeting, chrome windshield braces and half-moon hubcaps. Trapp and studio special effects man Norm Breedlove (father of land-speed-record-setter Craig Breedlove) modified the car to give it an elongated engine compartment, palladian-style brass radiator with “Porter” script, a spare tire mounted on the running board, outboard fuel tank and antique cane-clad trunk. (It was later fitted, as needed, with special effects hardware, such as an oil tank drip to simulate a smoking engine and "tear ducts" in the headlamp bezels.) Off-camera operation of electrics was by umbilical cable. The signature features gave it an anachronistic look, resembling cars of earlier eras.
The power train was the rod-grade 283 cu in V8 (Chevrolet small-block) engine mated with Powerglide automatic transmission. The "Porter" was registered (as a modified Ford) in 1964 with the contemporary yellow-on-black California license plates PZR 317 evident throughout the show's run. Though it bore a few design similarities with the FRP Porter, which may have suggested the television car's moniker, it is rumored that the car was named after the show’s production manager, W. A. Porter.
When series production was approved, the Grabowski rod was retained as the "hero" car, and a second — "stunt", or special effects — car was commissioned and built by celebrated car customizer George Barris, whose Barris Kustom Industries licensed it to AMT for model kit production (an inaccurate rendering) and also toured it after series wrap with other of his creations. The stunt car, not conventionally driveable, was ingeniously equipped with apparatus to let Mother "drive herself" via a system of levers and mirrors operated by a short human driver concealed on a tractor seat below the removed rear floorboards. It also had other special mechanical features, such as gimbaled headlamps.
Both cars had the dashboard-mounted radio head with flashing dial light through which Mother "talked" (though only to her son). These scenes were filmed with a stand-in; actress Ann Sothern’s voice was dubbed to the soundtrack in post-production. Generally, the hero car was used for driving shots and close-ups, and the stunt car for long shots and special effects sequences. Either was available as a stand-in in case of mechanical breakdown on set. Though made to represent one car, they can be distinguished by minor details, and actually appeared together in one episode.
Additionally, a third car was used in filming, representing both the dilapidated car-lot Porter of the pilot and, in another episode, a “1932 Porter”. This car may not have been complete, and its existence and whereabouts are unknown.
The hero car is currently[when?] located in Edmonton, Alberta, Canada. The stunt car was once owned by casino giant William Harrah, who had one of the largest special-interest and antique auto collections of all time in Reno, Nevada. After Harrah's death in 1984, the auction catalogue advertised the lot as having a carnation red body with white top and created from parts of a Ford Model T, a Maxwell, a Hudson and a Chevrolet. Following ownership by Rear View Mirror Museum (Nags Head, North Carolina) and later Herbie's Antique & Classic Car Museum (Mount Pleasant, South Carolina), the stunt Porter is currently[when?] on display in Star Cars Museum (Gatlinburg, Tennessee).