Used car buying guides

Plain answers to the things buyers ask before they hand over money. Each one ends with the questions to put to the seller.

• What Cat N and Cat S mean on a used carCat N and Cat S are insurance write-off categories. What each one means, whether the car is safe to buy, and what to ask the seller.
• Mileage went down between MOTs: mistake or clocking?A lower mileage at a later MOT is either a typing mistake at the test or a sign the reading was changed. How to tell which, and what to ask.
• Buying a used car with outstanding financeIf a car is still on finance, the lender may own it, not the seller. How to check before you buy, and where a private buyer stands.
• What to ask a private seller before you travelThe questions that save a wasted journey: ownership, write-offs, mileage, service history and finance, and why each one matters.
• How to check a V5C logbook when buying a carWhat to look for on the V5C: the watermark, the serial number, the keeper's details and the VIN, and what a recently issued logbook can mean.