Very well known failure, just search for "BMW Z3 subframe failure". it is a design flaw by BMW that affects a lot of Z3's through all model years. Mine started to pop one weld at 88K miles. It can cause the rear alignment to be off, in worst case the trunk floor is torn out and the differential falls to the ground. Clunking from the back while shifting in the first two gears is one indicator this damage is not far away. This is one forum thread that describes the issue well: Https://www.bimmerforums.com/forum/showthread.php?1979601-subframe-trunk-floor-differential-mount-failure

- Austin, TX, USA

The contact owns a 1999 BMW Z3. After the vehicle was started and placed into reverse, a clanking sound emerged from the rear end without warning. The vehicle was not diagnosed or repaired. The VIN was excluded from NHTSA campaign number: 99V272000 (power train). The manufacturer was notified of the failure. The failure mileage was 140,000.

- Gretna, LA, USA

The rear differential housing is separating from the subframe of the car, under or near the trunk area. This is a well documented issue with the Z3 series of vehicles. This could be a safety hazard while operating the vehicle if the read differential separates from the subframe, and could cause a hazard to other motorist. This appears to be due to a design flaw. The frame was designed for a 1.9L engine, and BMW did not redesign the subframe to allow for the larger engines it later sold in the Z3 series of cars. BMW also had this same issue on 3xx series of vehicles, and agreed to repair those cars due to a class action law suite settlement. BMW should be held accountable for the design issue, and acknowledge the safety hazard.

- Simpsonville, SC, USA

The contact owns a 1999 BMW Z3. The contact stated that the vehicle was increasingly hard to control and the vehicle was taken to a local repair facility for an alignment. The mechanic advised the contact that the rear differential had failed and was causing the wheels to fracture from the sub frame. The mechanic also advised the contact of the recall associated with NHTSA campaign id number: 99V272000 (power train: Driveline: Differential unit). The manufacturer was contacted and the contact was advised to have the vehicle towed to the dealer. The vehicle was towed and the contact was awaiting diagnosis and repairs. The failure and current mileage was 105,000.

- Vancouver, WA, USA