Given the circumstances and the fact it has been serviced in accordance with the schedule since, the missing first service will have a minimal impact on the car’s value if it didn’t see much use during Covid-19, so the dealer’s offer is fair if the car didn’t get driven much during that period. If it missed a service and was driven 40,000 miles between oil changes, however, that’s a different matter. If it concerns you, then the Kadjar is a popular model and there will be plenty of other examples out there with FSH and a similar mileage.