Hard to say, but Oreca states in their press release, that there are already teams working on R4 cars: "Other teams have confirmed entering different cars equipped with the R4 kit in Latin America with RC Competicion (Argentina), but also in Africa with Rally Technic (South Africa). Several programmes have emerged in Europe too: Finland (Tahkomobili), Lithuania (Pro Racing), Austria (Signed Streets Motorsport), France (Milano Racing) and so Spain (ASM Motorsport)."
via https://www.oreca.com/en/news_oreca/...pionship-2019/