2004 Mercedes-Benz SLK 1.8L Petrol · RX54 AOB

A pattern of corrosion‑related brake‑line deterioration and occasional structural failures defines this SLK’s MOT history; the 2025‑10‑16 test passed but still flagged all rear brake pipes as corroded, while earlier years recorded a fractured rear coil spring, a severely worn nearside front suspension arm and ball‑joint, and multiple headlamp defects. The record shows a shift from major safety‑critical failures in 2022‑2023 to a cleaner pass in 2025, suggesting that the most serious faults have been addressed but that corrosion on the brake‑line network remains an unresolved, recurring issue. At 91,857 mi the car averages just over 4,000 mi per annum, well below the typical usage for a 22‑year‑old vehicle. Such low mileage often points to periods of limited running or storage, which can accelerate rubber and metal ageing even when the odometer reads modest figures. The relatively sparse testing interval between 2020 and 2025 (annual checks) does not reveal any abrupt mileage spikes, but the combination of age and low use means that seals, hoses and bushings may have deteriorated despite the low total distance. For a prospective buyer the foremost concern is the corrosion on all rear brake pipes and the thin rear pads noted repeatedly. On a road test feel for any spongy or soft pedal response, especially under heavy braking, and listen for metallic hissing or fluid leakage at the rear under‑tray. A thorough visual inspection of the pipe interiors for rust flakes and greased corrosion is advisable, and replacement of the rear brake lines should be budgeted. The nearside front suspension arm that failed in 2023 warrants a full check of the lower arm bushings and ball joint for play or knocking, and the rear coil spring that fractured in 2022 should be inspected for fatigue cracks or uneven spring rates before committing to the purchase. Additional items to verify include the persistent oil leak around the gearbox (recorded in 2023 and 2024), which may manifest as oil spots on the under‑tray or a low oil level on the dip‑stick; the near‑legal tyre tread on the nearside rear and inner‑edge wear on the front tyres, which should be measured for uniformity and depth; and the slight front wheel‑bearing play noted in 2021, which can produce a humming or grinding noise when cornering at speed. Addressing these specific points with a qualified mechanic will clarify whether the vehicle’s remaining life aligns with the buyer’s expectations.