Number of previous owners wrong

Hello to all I bought a Volvo V50, registered today, I noticed that the number of vehicle owners in the letter did not match what the dealer said to me. Concretely: “2 vehicle owners”-on the letter with my registration is “number of previous owners 3”, i.e. I am 4th hand. I telephoned with the seller, confessed his “thinking error”, but said casually: is not so bad or relevant with regard to vehicle price. Exactly there lies m my question: Since I still want to keep the car, can I ask for a “renegotiation”? if yes: is there an approximate value of what you can deduct? MfG P.S.: his first offer: used winter bikes and things are done… if you want to keep the car in order to be able to keep it.