Not helpful for dealing with this now, but helpful for the future, does your car have a speed limiter button? If you set that for the speed limit, you will never be caught again.
Are you sure about that?
If you know enough to set the limiter in the first place, surely it's better to drive within that limit and keep a lookout for changes rather relying on technology that can fail?
Saying "My speed limiter failed" is no defence to a speeding charge
I use mine all the time, I can concentrate on the road and not my speedometer. It will hold speed on downhill sections.
