An interesting story my bro pointed me at.
I have heard of similar cases to that of the woman in the Astra: I read about a guy who was accused of riding his (unmodified) Triumph motorbike at an estimated speed of 185mph, but in court he produced the manufacturer's literature that specified a top speed of 160-odd. If I recall, they charged him as if he had been doing 150 or so, so was still a ban and hefty fine, but several thousand less than if he had been doing 185!
I have heard of similar cases to that of the woman in the Astra: I read about a guy who was accused of riding his (unmodified) Triumph motorbike at an estimated speed of 185mph, but in court he produced the manufacturer's literature that specified a top speed of 160-odd. If I recall, they charged him as if he had been doing 150 or so, so was still a ban and hefty fine, but several thousand less than if he had been doing 185!