Section 42. In proceedings under sections twenty-seven A, twenty-eight, twenty-nine, one hundred and eleven A and one hundred and thirty-nine of chapter two hundred and sixty-six, certified copies of any motor vehicle or trailer ownership records, including computer records, in the possession of the registrar of motor vehicles, attested by the registrar or his designee or, if the motor vehicle or trailer is registered or titled in another state, such records similarly certified by the keeper of records of the appropriate motor vehicle department, shall be admissible as proof of ownership of a motor vehicle or trailer and shall be prima facie evidence that the use of the motor vehicle or trailer was unauthorized. If the defendant rebuts such evidence, the commonwealth may be granted a reasonable continuance to enable the owner of the vehicle to be brought into court to testify.