I guess that must mean that someone has stolen another Macan S, put your plates on it, then broken it up to sell the parts. Or crashed and wrote off another Macan that had your plates on it for the insurance, and the scrapyard then had to inform the DVLA that the car had been scrapped. But, even if the VIN on the scrapped car has been faked to match the VIN on your car, there will be other tags that are unique to your car that have not been transferred to the car that was scrapped. Worth seeing what your Porsche dealer can to to help you speed up the investigation and prove that the scrapped car was not your car.