Many drivers have been obliged to leave a team during the season, even multiple World Champions Niki Lauda and Alain Prost were immune to being given the boot by a team. Following the discussions on the Nico retirement thread I thought I would list a few I can recall and if you have any of your own please feel free to add them. James Hunt - three years after taking the title James moved from McLaren to Walter Wolf racing for the 1979 season. The car was, reputedly, difficult to drive and he announced his retirement from F1 after the Monaco GP. Lots of rumours abound that he deliberately broke the car in Monaco to force retirement from the race and clearly his heart was no longer in it. Niki Lauda - Lauda never completed the 1977 season with Ferrari even though he had just won his second World Title for them. For 1978 and '79 he was at Brabham until practice at the Canadian Grand Prix where he announced himself "fed up with driving round in circles" and walked away. He came back in 1982 with McLaren and won the title again in 1984. Carlos Reutemann - After a very difficult season at Williams in 1981, where Reutemann lost out on the World Title in the last race of the season to Nelson Piquet, Carlos was to be team leader for 1982 following the retirement of Alan Jones. Reutemann raced for Williams in South Africa and Brazil before packing it in before the US GP at Long Beach. Wiki claims that tensions over the Falklands influenced Carlos' decision to leave the most British of F1 teams although Patrick Head believes he had simply had enough. Juan Pablo Montoya - Half way through the 2006 season JPM announced he would be driving in NASCAR in 2007. Ron Dennis took umbridge at this and Juan Pablo was "stood down" from the McLaren team. However, McLaren still had Montoya under contract so to be able to race in NASCAR that year he had to resign from receiving a payout from the team to escape the remainder of his contract. He duly did, ran some races in some the NASCAR feeder series and still finished 8th in the F1 title race that season. There must be some more?