In 1963 Parkes joined Ferrari as development engineer for their road cars, notably the 330 GTC, and also as a GT sports car driver. Following his absence from work after his serious F1 accident, he returned to Ferrari in 1969 to find the company partly under the control of Fiat and at that point decided to work for Scuderia Filipinetti as engineer as well as driver. His departure from Ferrari was partly due to Enzo Ferrari's refusal to allow him to return to F1 after his accident, claiming that he was too valuable as an engineer.