If any person at any time on or after the day appointed by regulations under section 51(1) of this Act sells, supplies or offers to sell or supply a goods vehicle of a class to which those regulations apply and it does not appear from one or more certificates in force at that time under section 47 of this Act that the vehicle complies with all the relevant type approval requirements prescribed by those regulations, he shall be guilty of an offence.
A person shall not be convicted of an offence under this section in respect of the sale, supply or offer of a vehicle if he proves—
that it was sold, supplied or offered, as the case may be, for export from Great Britain;
that he had reasonable cause to believe that it would not be used on a road in Great Britain or would not be so used until it had been certified as aforesaid; or
that he had reasonable cause to believe that it would only be used for purposes or in any area prescribed by the Secretary of State under section 46(5) or 51(5) of this Act.
Nothing in subsection (1) above shall affect the validity of a contract or any rights arising under or in relation to a contract.