There are three confirmed manufacturers working on rally3 car and one was thinking about it. This is info from the time when this new class was introduced to the regulations.
Who's the 4th? From what I've heard the 3 are those with Rally 4 (or 5) cars: Ford, Peugeot and Renault; apparently Renault may take a while as their main aim is to get the Clio Rally 4 car ready for 2021.
Missed a chicane
[WRC] Delfi Rally Estonia 2025