2005 Mazda 6 2.0L Petrol · DE05 LJC

The defining mechanical concern in this Mazda 6's history is a serious corrosion issue at the rear structural mounting points, which emerged sharply on the January 2025 test before being resolved by the most recent assessment on 19 January 2026, where the vehicle passed with no defects recorded. The 2025 failure flagged excessive corrosion on both the nearside outer and inner vehicle structure within 30 centimetres of a body mounting sill, alongside perished anti-roll bar linkage dust covers on the rear axle and a non-compliant rear registration plate. The fact that the 2026 test recorded no advisories indicates the sill corrosion was either professionally repaired or treated to bring the vehicle back inside structural limits, but the underlying chassis integrity in that area demands close physical inspection, as corrosion work completed just to pass an MOT can sometimes mask deeper substrate loss rather than fully remediating it. The earlier clean passes in 2024 and 2025 suggest the structural deterioration appeared rapidly rather than gradually, which is characteristic of sill corrosion accelerated by salt ingress behind cosmetic trim or blocked drainage channels. With 107,271 miles spread across twenty-one years, this car has averaged only around 5,100 miles annually, a notably low rate of accumulation that places it firmly in light-use territory. Such low annual mileage typically translates to extended periods of stationary or short-journey use, conditions that can accelerate ageing of certain components even as they preserve engine and gearbox life. The two failed tests in close succession on the same January day in 2025 indicate either deliberate presentation for re-test after repair work or an interrupted inspection cycle, while the rapid turnaround to a clean pass twelve months later demonstrates the sill corrosion was actively addressed. Mechanically, low-mileage Mazda 6s of this generation often suffer more from dried-out rubber suspension bushes, perished coolant hoses, and stale brake fluid than from outright mechanical wear, so the relevance of these patterns should be prioritised during any assessment. Given the rear anti-roll bar linkage dust cover failures recorded on both sides, particular attention should be paid to the rear suspension on a test drive. With the vehicle stationary, visually inspect the small rubber boots covering the drop links where they meet the anti-roll bar, checking for splits, grease leakage, or perished material. On the move, listen for clonking or rattling noises emanating from the rear axle over uneven road surfaces, particularly when changing direction or traversing speed humps, as a worn ball joint within a split dust cover will produce metallic knocking that worsens progressively. The rear anti-roll bar itself should be inspected for play by hand with the wheel raised, and any looseness in the linkage would indicate imminent replacement. The sill corrosion flagged on the nearside rear demands hands-on inspection rather than cursory visual appraisal. Crawl underneath the vehicle and probe the inner and outer sill sections, paying particular attention to the mounting point areas within thirty centimetres of the floor pan, where MOT examiners focus their measurement. Any bubbling under the paint, flaking surface rust, or visible metal perforation would indicate the previous repair was cosmetic rather than structural. On a test drive, listen for any wind noise, water ingress from the boot area after rain, or uneven body rigidity when closing doors firmly. Additionally, given the dangerously failed offside rear tyre recorded in January 2026 from structural separation, inspect all four tyres for bulges, uneven tread wear, or sidewall damage, and verify they are of matching age and brand, as a single structural tyre failure on a low-mileage car can sometimes indicate prolonged under-inflation or extended standing periods allowing flat-spotting and sidewall degradation.