Here you will find a list of common faults and approximate costs to repair.
BMW Z4 convertible roof not working
The most common problem with the Z4 roof failing to operate is the motor becoming severely corroded due to water ingress. To repair this fault we need to remove the complete roof assembly from the car, remove the motor, fit the new motor and then refit the roof. This problem is caused by debris (leaves) blocking the motor recess drain hole thus submerging the motor in water.
The cost of this repair is approximately £700.00 + vat incl parts and labour and can usually be carried out in one day.