2009 Toyota IQ 1.0L Petrol · SM09 FHT

A clear pattern of progressive underside corrosion dominates the mechanical history of this 2009 Toyota IQ, with structural and brake-related failures appearing across two consecutive test cycles in 2022 and 2024 that have now been resolved, while advisories relating to corrosion continue to accumulate. The most recent test on 19 May 2026 was a pass, but it carried an advisory for general underbody corrosion alongside a note that both front tyres were worn close to the legal limit on their edges, suggesting the front geometry or tracking may be drifting as corrosion takes hold. The 2024 cycle is particularly significant: the vehicle was failed on 13 June 2024 for excessively corroded nearside rear and offside front brake pipes, a dangerously fluctuating rear service brake, and an excessively corroded inner sill mounting point that was reducing structural strength, before passing on 17 June 2024 once those repairs were evidently completed. A further failure in March 2025 for a split anti-roll bar linkage ball joint dust cover, accompanied by advisories on both front and rear subframe corrosion, demonstrates that even after the brake and structural repairs, the chassis hardware remains an ongoing maintenance liability rather than a resolved issue. With 54,170 miles recorded against an age of approximately seventeen years, annual mileage works out at roughly 3,186 miles per year, which is well below the typical accumulation rate for a car of this vintage. While low annual mileage reduces wear on internal combustion components and the automatic transmission, it does not protect the chassis and underbody from the oxidation that has been consistently flagged since at least 2022, when advisories for corroded subframes, corroded suspension components, and a corroded underside first appeared alongside borderline subframe corrosion. The 2022 entry also recorded dangerous-level corrosion to the offside front subframe mounting prescribed area, indicating that this deterioration had already reached a critical stage and was repaired prior to the subsequent pass. Mechanically, this usage profile points to a vehicle that has likely been used predominantly for short urban trips rather than long-distance driving, with the car potentially standing for extended periods between MOTs, and the DVSA record shows roughly a year-and-a-half gap between the 2023 and 2024 tests which is consistent with a laid-up period. A prospective buyer should treat the underside of this vehicle as the primary inspection area, paying particular attention to the inner sills, both front and rear subframes, and all visible brake and fuel lines for any renewed corrosion that may have advanced since the most recent test. During a test drive, listen for any clonks or knocking from the front suspension over uneven surfaces, as worn anti-roll bar linkages and bushes have already been flagged, and feel for any pulling to one side under braking which would suggest a binding caliper or warped disc given the recorded brake fluctuation history. The rear brake circuit in particular warrants close attention, with brake pedal feel and any sponginess or excessive travel worth checking carefully, alongside a visual inspection of the flexible hoses for fresh rust around the ferrules. It is also advisable to place the car on a ramp and inspect the engine sump and gaskets for active oil seepage, as a non-excessive oil leak was noted in 2024, and to verify that the rear exhaust mounting and flexi joint have been replaced, since the exhaust system showed both a minor gas leak and a defective mounting in the 2024 record. Finally, with both front tyres having been flagged as edge-worn on the most recent test, a four-wheel alignment check should be considered after purchase to rule out any tracking or suspension geometry issues accelerated by the corroded components.