Between 1941 and 1944 Renault was placed under the technical directorship of a francophile engineer, Wilhelm von Urach (between 1927 and 1940 employed by Daimler Benz) who failed to notice the small car project emerging on his watch.

[7] A design team led by the company's technical director, Fernand Picard, recently returned from Renault's aero-engine division to the auto business[7] and Charles-Edmond Serre, who had been with Renault for longer than virtually anyone else, envisioned a small, economical car suitable for the period of austerity expected after the war.

[7] However, because the Germans had forbidden work on any new passenger car models, the 4CV development was defined as a low priority spin-off from a project to develop a new engine for a post-war return of the company's 1930s small car, the Juvaquatre: departmental bosses installed by the Germans were definitely not to be trusted in respect of "Project 106E", while von Urach, their overlord, always managed to turn a blind eye to the whole business.

The Gestapo transferred him to Metz for interrogation, but the city was deserted because of the advancing allied front and the Germans abandoned their prisoner.

Lefaucheux insisted that the meetings would have absolutely no influence on the design of the Renault 4CV, and Porsche cautiously went on record with the view that the car would be ready for large scale production in a year.

As soon as the 4CV project meetings mandated by the politicians had taken place, Porsche was arrested in connection with war crimes allegations involving the use of forced labour including French in the Volkswagen plant in Germany.

Porsche was accompanied on his visit to the Renault plant by his son Ferry, and the two were offered release in return for a substantial cash payment.

Volume production was said to have commenced at the company's Billancourt plant a few weeks before the Paris Motor Show of October 1947, although the cars were in very short supply for the next year or so.

[14][15] On the 4CV's launch, it was nicknamed "La motte de beurre" (the lump of butter); this was due to the combination of its shape and the fact that early deliveries all used surplus paint from the German Army vehicles of Rommel's Afrika Korps, which were a sand-yellow color.

Despite an initial period of uncertainty and poor sales due to the ravaged state of the French economy, the 4CV had sold 37,000 units by mid-1949 and was the most popular car in France.

Across the Rhine 1,760 4CVs were sold in West Germany in 1950, accounting for 23% of that country's imported cars, and ranking second only to the Fiat 500 on the list.

Claimed power output increased subsequently to 21 hp (16 kW) as increased fuel octanes allowed for higher compression ratios, which along with the relatively low 620 kg (1,370 lb) weight of the car which enabled the manufacturer to report a 0–90 km/h (0–56 mph) time of 38 seconds and a top speed barely under 100 km/h (62 mph).

[2] The rear mounting of the engine meant that the steering could be highly geared while remaining relatively light; in the early cars, only 2¼ turns were needed from lock-to-lock.

[20] Other countries where 4CVs were assembled included Australia, Belgium, England, Ireland, Japan (where the Hino-assembled cars gained a reputation for superior quality[2]), Spain and South Africa.