A motor vehicle may not be used on a public road if it is fitted with a spot lamp, which can be so adjusted as to enable a beam of light emit therefrom to be deflect in any direction;

Provided that a spot lamp which is adjustable—

may be fitted and used for official purposes on any ambulance, rescue vehicle, fire- fighting vehicle, police vehicle or traffic control vehicle,

may be fitted to a vehicle owned by a medical practitioner or veterinarian, and used for professional duties only; or

may be fitted to a breakdown vehicle or a vehicle employed in connection with the supply of electricity or other public essential services: Provided that it is used solely at the scene of an accident or breakdown or for the examination of overhead telephone, telegraph or power lines.