What are the best used cars to buy? Criteria, reliability reports and a checklist

Why there is no ranking of best models here

We do not publish a ranking of the best used cars, because a ranking without a source cannot be checked. The reliability reports measure different things: the TÜV Report defects found at inspection in Germany, ADAC roadside call-outs, Which? what owners report in the United Kingdom. So we do not merge them into one league table; we show each with its name, date and limits.

Which reliability reports exist and what they measure

We read three reports for this article: the Which? survey (United Kingdom, 63,334 drivers), the TÜV Report 2026 (Germany, 9.5 million inspections, overall defect rate 21.5%) and the ADAC Pannenstatistik 2026 (158 models from 27 manufacturers, almost half of all cases caused by the 12-volt battery). The reports measure different things, so they cannot be compared directly.

The two German reports describe cars driven in Germany. Many models are the same in the UK, but mileage and servicing can differ, so treat a report as a warning sign. Which? is the only UK owner survey among the three, and its detailed results sit behind a membership.

Which models lead the TÜV Report 2026 for 2 to 3 year old cars

According to TÜV Rheinland (20 November 2025), the Mazda 2 is the overall winner among 2 to 3 year old cars on the German market. The class leaders are the Fiat 500E (mini), the BMW 1 and 2 Series (compact), the Mercedes-Benz C-Class (mid-size), the Mercedes-Benz B-Class (van-type MPV) and the Volkswagen T-Roc (SUV).

This applies to 2 to 3 year old cars on the German market. A class winner is no guarantee for the car in front of you. For older cars, look for results for the age of the car you are buying.

Six criteria for your own shortlist

When you choose a used car, check six things: the reliability of the model and year in a named, dated report, the history of the individual car (service book, number of owners, chassis number), the 12-volt battery, running costs, parts availability and, for electric and hybrid cars, a battery health report with the battery warranty. The first is about the model; the rest are about the individual car and its costs.

A checklist for the actual car

Check the individual car in six steps, from the cheapest check to the most expensive: a report on the model, the service book and invoices, a comparison of the chassis number, a battery test with fault codes read through OBD, a test drive that includes a stretch of fast road, and an independent inspection before you pay and sign the contract.

1. Find a report for the model, year and engine and note the weak point it names.
2. Ask for the service book and invoices and compare them with the mileage in the advert.
3. Compare the chassis number in the papers with the one on the car.
4. Have the battery tested and read stored fault codes with an on-board diagnostics (OBD) reader. It reads faults; it is not proof of mileage.
5. Take a test drive that includes at least one stretch of fast road, and check the brakes.
6. Book an independent inspection before you pay, then sign the contract.

The full buying process, from documents to contract, is covered in the blog index.

What this means for a buyer and for a dealer

For a buyer

Use the reports to rule out models with a known weakness, then compare adverts. In our view, the history of one particular car says more about future costs than a model ranking does.

For a dealer

Choose three to five models that the reports do not flag as problematic and search for them systematically. WeltScout monitors 50+ portals in 14 countries and sends a WhatsApp or e-mail alert when a new listing matches your criteria. It checks listings once or twice a day, depending on the plan. The trial needs no card, and the Business plan starts at EUR 129.90 per month excluding VAT.

Frequently asked questions