2009 Toyota Aygo 1.0L Petrol · FN09 SYR

A pattern of gradual corrosion and underbody degradation defines the mechanical outlook for this 2009 Toyota Aygo, supported by advisories that have accumulated steadily across consecutive MOT tests. The most recent attempt on 12 December 2025 initially resulted in a failure due to the tester being unable to complete the emissions check, an outcome often linked to exhaust or catalytic system faults on a vehicle of this age, though a retest the same day returned a pass. More telling is the persistent advisory trail: underbody corrosion was first flagged in 2022 across all testable surfaces, followed in 2023 by specific advisories on the offside rear sill and corrosion around both rear axle mounts, along with a binding offside rear service brake. The 2024 test noted underseal, suggesting a previous attempt to manage the corrosion, though the underlying issue is structural in nature. The trajectory points to a small city car entering the typical late-life rust phase common to its platform. With 85,368 miles recorded over approximately 17 years, this Aygo has covered around 5,000 miles annually, a notably low figure that implies either limited daily use or extended periods of standing. Mechanically, such low mileage reduces wear on major drivetrain components and helps preserve the small 1.0-litre engine and manual gearbox, but it also accelerates corrosion in areas that benefit from regular use, such as the brake calipers, wheel bearings, and exhaust hangers. The lack of mileage progression in recent test records is worth verifying directly with the seller, as accurate odometer readings are essential for assessing whether standing time has degraded ancillary systems like the cooling circuit, fuel system seals, or underbody protection. For a prospective buyer, the immediate priority is a thorough underbody inspection, ideally on a ramp, to assess the extent to which the advisory corrosion around the rear axle mounts and sill has progressed since 2023. Rust in these prescribed areas can advance significantly between MOT tests, particularly where salt exposure has been consistent. On a test drive, pay close attention to clonking or knocking from the rear suspension over uneven surfaces, which would suggest the corroded axle mount areas are losing structural integrity. The offside rear service brake binding noted in 2023 should be specifically evaluated by checking for uneven brake disc wear, excessive heat from that wheel after driving, and any pulling or dragging sensation when releasing the parking brake. Given the emissions test was initially failed in December 2025, a pre-purchase diagnostic read of lambda sensor values and catalytic converter efficiency would be prudent, as exhaust system deterioration is common at this mileage and age. Finally, the deteriorated nearside front CV boot flagged as a minor defect at the latest test is an inexpensive item to replace but should not be ignored, as a torn boot allows grease loss and eventual joint failure, typically announced by a clicking noise on full lock during low-speed manoeuvres. With the vehicle likely to be approaching the boundary where MOT advisories transition into failure items, particularly around corrosion, a realistic budgeting for rear sill and axle mount welding repairs within the next one to two test cycles should be factored into any purchase decision. Provided the bodywork remains fundamentally sound and the mechanical components receive targeted attention, this Aygo should continue to serve as economical transport, but it is no longer a candidate for a buyer seeking a corrosion-free example.