Hello, the following thought game: I buy a new car from a dealer in Germany for any brand. Then I have the dealer compared to the warranty (now: material defects liability) of 24months. Completely independent of the warranty of the manufacturer. I know the subtleties on the subject of material defects liability, e.g. that the dealer can shorten it for new goods to 12 months and that only within the first 6 months the seller must prove that the product is missing Now I buy a car and drive 80.000km in the first 5 months. I do not have any maintenance and then suffer a motor damage within the first 5 months. Now the common opinion is: “Guarantee only exists if you also comply with the maintenance regulations of the manufacturer!”, i.e. an oil change after 15,000km or something. In this case, however, I do not want to use the warranty promises of the manufacturer, but simply the liability for defects of the product. Now the question is: Is (or can) the liability for defects linked to conditions? Like, for example, in the case of a car to maintenance, or does the “product” have to function properly for 6 months without the intervention of the end user?