Renault built at least running prototypes. They were painted in muted greys and dark blues and were tested extensively around the Billancourt factory and in the Alps. Contemporary reports from Renault test drivers (declassified decades later) describe the DF264 as a paradox:
"Zero volts, Dad," Theo said, stifling a yawn.
Sometimes the code is stored in "memory" due to a temporary voltage drop (e.g., a weak battery). Clearing the code with a diagnostic scanner may resolve the issue if it does not return.
"Still nothing."
To understand the DF264, one must understand France in the early 1950s. After WWII, Renault was nationalized under Pierre Lefaucheux. The company was enjoying massive success with the 4CV (launched in 1947), a rear-engined, four-door "people's car" that was putting France back on wheels. However, the 4CV was tiny. Its 760cc engine was economical but utterly unsuitable for the open road or for families who wanted a modicum of comfort.
If you want a short spec sheet (dimensions, exact hp/tq, injection type) for a specific year or variant, tell me the model year or serial number and I’ll fetch detailed specs.