"There currently exists a loophole that enables car offenders to escape prosecution because it is nigh on impossible to prove “whodunit”.

I would suggest that actually proving someone commited an offence before punishing them is more than a loophole.

"Anyone witnessing an act would record the time, date, place and registration number to the police who would then issue a notice to the registered keeper to discover who was driving"

And, in the the author's considered legal opinion, an uncorrobarated accusation is sufficient for a conviction?