Crespo started in the automobile business in Elx and Oriheula. He is a very religious person and a close friend of Francisco Camps, the former president of the Valencia Autonomous Government and who was prosecuted for corruption charges. Crespo chaired Alicante's Metal Board Directors Association (FEMP) until it was challenged in 2004. Also, he chaired the general Alicante's Board Directors Association COEPA from 2006 to 2009. During that period, Crespo was charged for making a € 813,000 hole in the association's accountability. From 2002 to 2009, he was also in charge of the Alicante's Trade Fair and left under a financial scandal. Despite Crespo's lack of studies, he was named CAM's CEO on June 2009.
Crespo was dismissed on July 22nd 2011, after the Bank of Spain intervened CAM. In his farewell speech, Crespo mentioned his mentor, Francisco Camps, describing him as an honest and righteous person.
Modesto Crespo, while being CAM's CEO, granted himself loans amounting to €7,89 millionCrespo is being investigated by the Bank of Spain and has an admitted complaint to the High Court.