Question: Which Formula One car besides the Tyrrell P34 was one of the most radical entries ever to succeed in F1 competition, that used flat panel heat exchangers? 
Sentence (from "Covini C6W"): The project was started in 1974 but abandoned shortly after, and left dormant into the 1980s due to the lack of availability of low-profile tires at the time.
Relevant evidence: No