BMW Z42003 · 3.0L PETROL

The 2022 test at 101,396 miles shows the vehicle remains roadworthy, but the maintenance picture is mixed. A clean pass in 2020 with zero defects suggests competent upkeep at that point. The 2021 failure for an unsecured bonnet and low handbrake efficiency, followed by a retest pass on the same day, indicates a quick fix rather than deeper investigation into the braking system. By mid-2022, the tester flagged corroded brake pipes covered in grease or contaminant, along with perished inner sidewalls on both front tyres. These are not trivial consumable issues. Corroded brake lines compromise hydraulic integrity, and the presence of grease suggests either a botched repair or contamination masking a leak. The trend is not worsening in a linear sense, but it reveals intermittent neglect rather than consistent preventative care. The mileage profile is notably low. Between June 2019 at 93,407 miles and July 2021 at 98,140 miles, the car covered roughly 4,733 miles in two years. It then sat completely stationary for twelve months, recording 101,396 miles in June 2022 with no intervening tests. That is a 3,256-mile jump after a full year of apparent inactivity, and no further tests have been recorded since. The annual average of around 4,400 miles is well below typical use, which can preserve bodywork but also encourages moisture accumulation in brake fluid, coolant, and exhaust components. Long periods standing risk flat-spotted tyres, seized calipers, and stale fuel system deposits. A buyer should prioritise a thorough inspection of the braking system. The 2022 advisory on corroded and contaminated front-to-rear brake pipes demands a close look at the entire hydraulic circuit, including flexible hoses and the master cylinder. Front tyre sidewall damage was flagged in both 2021 and 2022, suggesting either repeated fitment of budget rubber or a suspension geometry issue such as worn tracking rod ends or collapsed front bushes causing uneven loading. The handbrake efficiency concern in 2021, though resolved for the retest, warrants checking the rear caliper mechanisms and cable adjustment, as binding is common on low-use BMWs. The stationary period also raises questions about fluid condition. Brake fluid, coolant, and power steering fluid should be tested or replaced, and the exhaust system inspected for internal condensation corrosion. Despite the low mileage, this Z4 shows signs of sporadic rather than diligent ownership. A pre-purchase inspection by a BMW specialist is strongly advised.