2015 Audi A6 2.0L Diesel · KN15 AAK

The most recent MOT test completed on 30 December 2025 resulted in a pass, but it introduced a notable advisory regarding corrosion on the rear sub-frame. While the vehicle maintained a clean record through 2023 and 2024, the progression from consumable wear advisories in 2022 to structural corrosion in 2025 suggests a shift in the maintenance profile. The overall trend indicates that while the vehicle has been kept roadworthy, it is now entering a phase where structural oxidation is becoming a factor, which requires closer monitoring to ensure it does not escalate into a major failure. At 146,557 miles, this Audi A6 has covered a significant distance for an eleven-year-old vehicle, averaging approximately 13,323 miles per annum. This level of usage is higher than the UK average and suggests consistent, heavy use. From a mechanical standpoint, high mileage of this nature places increased stress on the drivetrain, suspension components, and various seals. You should anticipate that components such as the suspension bushes, shock absorbers, and engine mounts may be nearing the end of their functional lifespan, and the cumulative wear on the engine and transmission should be considered when evaluating the vehicle's long-term reliability. The advisory concerning the rear sub-frame is the most critical point for inspection. During your test drive, listen intently for any rhythmic thumping, clunking, or metallic knocking from the rear axle, particularly when driving over undulations or potholes, as this could indicate that the corrosion is affecting the sub-frame's ability to hold suspension components securely. It is highly recommended to inspect the underside of the vehicle for the severity of the rust; if the corrosion appears deep or flaky, it may eventually necessitate costly structural repairs or a complete sub-frame replacement to pass future MOT inspections. Furthermore, given the previous history of worn tyres and braking components, you must conduct a thorough physical inspection of the running gear. Check the brake discs for excessive lip or scoring and ensure there is no vibration or shudder through the brake pedal during deceleration, which would indicate warped discs or binding calipers. Examine the tyres for uneven wear patterns that might suggest alignment issues caused by worn suspension components. Finally, because of the high mileage, verify that the service history confirms regular oil changes and that essential fluids, such as the coolant and brake fluid, have been replaced according to manufacturer intervals to mitigate the risks associated with high-use ageing.