A colleague was in this position but in his own vehicle. He didn't deny the offence but couldn't tell whether it was him or his wife driving (was a van although he does moan like a woman).

He took legal advice and was advised to ask the police who they intend to prosecute as he couldn't be sure of the driver. The solicitor told him to let them take it to court. In the end they dropped the case before court and sent a stern warning.

I would ask who they intend to prosecute as you do not know and the evidence does not allow for identification. I don't know if its myth or fact but I thought something changed meaning that if a driver can't be determined the registered keeper was prosecuted.

Maybe try a solicitor that offers a free 30min consultation.

Matt