The term 'Dud of a Car' can be summarized as a vehicle that is of poor quality and unreliable. The crossword solution for this term is 'LEMON', which is a slang term used to describe a car that is defective or unsatisfactory. It is believed that the term originated in the early 1900s when cars were first being mass-produced, and buyers would receive a LEMON if they purchased a car that was faulty or had major defects.