Dutch law says goods that are sold must 'conform to the agreement' (art. 7:17 of the Civil Code, BW). A car must therefore have the properties you as the buyer could expect. What was agreed and said counts, but so does what is normal for a car of that age, mileage and price. You can expect less from a fifteen-year-old car than from a two-year-old one.
Why it matters when buying or selling
- From a dealer: in a consumer sale, the seller cannot exclude statutory conformity. A defect that shows up within 1 year of delivery is presumed to have existed already (the presumption of defect).
- Between private persons: the rule applies too, but the parties can limit it with clear agreements, for example by excluding any warranty. Hiding known defects is never allowed.
- What you promise counts: the mileage, service history and options you mention in your listing shape what the buyer may expect. Be precise.
- Complain in time: report a defect quickly. In a consumer sale, reporting it within two months of discovery is always in time.
Put agreements in writing in a sale contract.