You cannot describe a vehicle as being one thing and then sell it as something else. Trade descriptions act covers that, more info here
http://www.berr.gov.uk/files/file8156.pdf[/QUOTE]
The Trades Description Act 1968 has been replaced by the Sale of Goods Act 1979, which has been amended several times since then.
The relevant part is section 14
14 Implied terms about quality or fitness
(2)Where the seller sells goods in the course of a business, there is an implied term that the goods supplied under the contract are of satisfactory quality.
(2A)For the purposes of this Act, goods are of satisfactory quality if they meet the standard that a reasonable person would regard as satisfactory, taking account of any description of the goods, the price (if relevant) and all the other relevant circumstances.
(2D)If the buyer deals as consumer ... the relevant circumstances mentioned in subsection (2A) above include any public statements on the specific characteristics of the goods made about them by the seller, the producer or his representative, particularly in advertising or on labelling.
(2E)A public statement is not by virtue of subsection (2D) above a relevant circumstance for the purposes of subsection (2A) above in the case of a contract of sale, if the seller shows that—
(a)at the time the contract was made, he was not, and could not reasonably have been, aware of the statement,
(b)before the contract was made, the statement had been withdrawn in public or, to the extent that it contained anything which was incorrect or misleading, it had been corrected in public, or
(c)the decision to buy the goods could not have been influenced by the statement.
To summarize: If something said in the advertising or labelling of a product affects whether the customer buys the product, then that becomes a relevant part of the contract and the product must conform to those statements. So if the sticker on the car says it is one owner, it must be one owner.