From what you have said do you think that your car could have been cloned?

https://www.moneysupermarket.com/car...s-car-cloning/

I would report it to the police & ask them if this could have happened i.e. prompt them to investigate this as opposed to them maybe thinking that you are merely trying to wriggle out of a speeding fine. Maybe worth also speaking to the DVLA & asking a few questions there i.e. were there any issues with the car before you bought it.

If you have little/no joy then, as has already been suggested on here, I would seek immediate legal advice.