The law changed so that the owner had to offer up details and/or show they had made a "diligent and documented search" to ascertain who the driver was. If they can not provide a definite answer, the charges are dropped. Only exception to this rule is company cars
Note that the police must make this request within 14 days of the offence, not 6 months to 2 years after the event, like Davenport Lyons are doing.
A defence that stands up in a criminal court, will stand well in a civil court