14.—(1) This paragraph applies to a vehicle—
(a)kept by a motor trader, being the holder of a trade licence who is a manufacturer of vehicles; and
(b)kept solely for the purposes of conducting research and development in the course of his business as such a manufacturer.
(2) The purposes for which such a person may, by virtue of the trade licence, use a vehicle to which this paragraph applies on a public road are the purposes of conducting research and development in the course of his business as a manufacturer of vehicles.
(3) Those purposes shall not be taken to include the conveyance of goods or burden of any description except—
(a)a load which is carried solely for the purpose of testing the vehicle or any of its accessories or equipment and which is returned to the place of loading without having been removed from the vehicle except for such purpose or in the case of accident; or
(b)any load built in as part of the vehicle or permanently attached to it.