Unknowingly sold total damage?!

Hello dear community, I didn’t know which subforum I should put this post in. I have a problem… and I sold a used Mustang about 6 months ago. This week I get an email from the buyer of the vehicle that this vehicle was a total damage import from the USA (“Probably more economical because nothing pointed to an old damage”. I myself knew of a small front damage that was also deposited in my purchase contract. When asked where he had this information, he said that a car fax could be requested in America and that all important information about the vehicle was stored there. Unfortunately, I didn’t know anything about it, so I had no idea that it was an economic total damage after all. At the moment, however, there are no defects about this vehicle that was caused by an old damage. the purchase has been deposited in the purchase contract. Do I have to refund the purchase price for it or could any of these still follow for me? As a guarantee text in the purchase contract states: “The vehicle is sold as inspected and under exclusion of liability for material defects, unless a certain assurance is made under point III. This exclusion does not apply to claims for damages from liability for material defects, which are due to a deliberate or grossly negligent violation of obligations the seller and the culpable injury to life, body and health. Insofar as claims consist of material defects liability against third parties, they are assigned to the buyer.” Gruss Skyline