Car due to go into Wessex Nissan again 15 April!! Done some research and there has been a bulletin issued by Nissan stating that when the high level brake light unit is removed for any reason a new rubber seal should be fitted. Failure to do this could result in water ingress. This is not mentioned in the vehicle handbook in the section setting out the procedure for changing the light bulb. Think that Wessex have not done the job properly in the past. Will provide update in due course.