If you bought it from a dealer who obviously knew it had been damaged and repaired because he bought it from the 'shunt and dent auction' then the dealer committed an offence under the The Consumer Protection from Unfair Trading Regulations May 2008 (CPRs). They incorporate The Sale and Supply of Goods to Consumers Regulations 2002 and contain a general prohibition against unfair commercial practices and, in particular prohibitions against misleading actions, misleading omissions and aggressive commercial practices. The Regulations are enforceable through the civil and criminal courts. The CPRs create an offence of misleading omissions which would not previously have been an offence if the consumer had not asked the right questions. So if a salesman knows a car has, for example, been badly damaged and repaired and does not tell the customer, he could later be held liable if the customer subsequently discovered that the car had been damaged and repaired.