2018 BMW M3 3.0L Petrol · W9 RNU

The 2018 BMW M3 presents a stable and improving maintenance trend, culminating in a clean pass on 23 July 2025 at 39,892 miles with zero defects. The preceding test on 20 July 2024 at 37,703 miles recorded two minor advisories: a chipped windscreen within legal tolerance and an offside front tyre worn close to the legal limit. Both items were evidently addressed before the 2025 test, demonstrating responsive upkeep. Across the full five-year record, there are no repeated structural, braking, or suspension failures, which is reassuring for a performance saloon of this age. The mileage profile is notably low, averaging roughly 4,986 miles per year over eight years. The vehicle covered 2,189 miles between the July 2024 and July 2025 tests, consistent with the long-term average and indicating steady, light use rather than prolonged standing. No anomalous gaps or sudden accumulation spikes appear in the record, suggesting regular annual operation without extended lay-ups that could cause dried seals or flat-spotted tyres. Despite the clean recent record, the 2024 advisory for an offside front tyre worn on the edge hints at possible alignment or suspension geometry wear, a common trait on driven axles of high-performance rear-wheel-drive cars. A buyer should inspect the inner shoulders of all four tyres for uneven wear and check front suspension bushes, track rod ends, and wishbone joints for play. The M3’s S55 engine and mechanical limited-slip differential demand scrutiny for oil leaks around the rocker cover, oil filter housing, and differential seals, particularly given the low annual mileage that can accelerate moisture build-up and fluid degradation. Corrosion inspection is equally critical. Examine the subframes, rear arch lips, sills, and jacking points for surface or structural rust, as low-mileage cars often sit for long periods without the heat cycles that help evaporate moisture. The braking system, including pad thickness, disc lip condition, and caliper slide pins, should be checked for seizure risk. A short test drive under load will reveal any binding, clunks, or drivetrain vibration that a static inspection might miss.