A subsequent iteration, marketed as the 126 Bis, used a horizontally oriented, water-cooled engine, and featured a rear hatchback with additional cargo space.

In early 2020, the 28-year production run of the Fiat 126 was counted as the twenty-sixth most long-lived single-generation car in history by Autocar magazine.

[3] The 126 shared its wheelbase and much of the mechanical underpinnings and layout with the Fiat 500, featuring a revised, slightly larger bodyshell designed by Sergio Sartorelli with improved safety and interior space.

The added interior space resulted from moving the starter from the top of the engine bellhousing to the side which permitted shifting the bulkhead/rear seat rearward approximately 10 cm, and the lengthening of the roof for rear-seat headroom.

The 126 BIS gained a hatchback to access an additional cargo space on the rear, which was freed by replacing the air-cooled engine with the water-cooled 704 cc 26 hp (19 kW) flat-twin.

[citation needed] The 126 did not achieve the popularity of the 500 in Western Europe, as the rear-engined layout was displaced by better packaging and handling front-engine, front-wheel drive cars.

For a brief period in the early 1990s, a German company called POP also offered convertible versions of the 126 BIS.

At first, it was almost identical to the basic model: differences included a higher chassis, a modified grille on the back, and the front indicator lenses that were clear white in Italy, but orange in other markets.

Upgrading a 45-amp hour battery from the Fiat 125p (1.5 Litre engine) improved the cold start reliability.

[citation needed] It was also successful in Cuba where it was one of the best-selling cars of its time and an estimated 10,000 are still registered today.

There was also an attempt at installing a small diesel engine (due to gasoline rationing) in the classic 126p body.

During the absolute rule of the PZPR, a private car was considered a luxury item due to limited availability and low salaries.

[14] In a top-down planned economy, decisions on whether a state-owned factory could produce a car were taken on political and not just economic grounds.

Thus, the PF 126p was intended to be the first real, popular, and affordable car to provide mobility for ordinary families.

The license was bought after the rise to power of a new PZPR leader, Edward Gierek, who wanted to gain popularity by increasing consumer spending after the austerity period under Władysław Gomułka.

During holidays, it was common to see families of four driving PF-126s abroad with huge suitcases on a roof rack; sightings of PF-126s towing a small Niewiadów N126 caravan especially designed for the PF 126 were also occasionally reported.