 During the 1983 season, McLaren worked with Techniques d'Avant Garde and Porsche to develop a turbocharged V6 engine built to John Barnard's specifications and the MP4/1D was the test mule.Later in the season at the Dutch Grand Prix at Zandvoort the Cosworth-powered MP4/1C was replaced by the TAG-powered MP4/1E, which was essentially also a test mule that competed in only 4 races; according to Watson in an interview given in 2009 this was a car that was forced into appearing at the Dutch Grand Prix after political maneuvering by Lauda.He went to Marlboro executive Aleardo Buzzi (the man responsible for giving McLaren their primary sponsorship money), behind the back of the McLaren team and complained extensively to Buzzi about the uncompetitiveness of the team without a turbo engine.