137 Supplementary provisions relating to s. 136.E+W+S
(1)A sidecar attached to a motor vehicle shall, if it complies with such conditions as may be specified in regulations made by the Secretary of State, be regarded as forming part of the vehicle to which it is attached and not as being a trailer.
(2)For the purposes of section 136 of this Act, in a case where a motor vehicle is so constructed that a trailer may by partial superimposition be attached to the vehicle in such a manner as to cause a substantial part of the weight of the trailer to be borne by the vehicle, that vehicle shall be deemed to be a vehicle itself constructed to carry a load.
(3)For the purposes of that section, in the case of a motor vehicle fitted with a crane, dynamo, welding plant or other special appliance or apparatus which is a permanent or essentially permanent fixture, the appliance or apparatus shall not be deemed to constitute a load or goods or burden of any description, but shall be deemed to form part of the vehicle.
(4)The Secretary of State may by regulations vary any of the maximum or minimum weights specified in section 136 of this Act; and such regulations may have effect—
(a)either generally or in the case of vehicles of any class specified in the regulations, and
(b)either for the purposes of this Act and of all regulations made under it or for such of those purposes as may be so specified.
(5)Nothing in section 86 of this Act shall be construed as limiting the powers conferred by subsection (4) above.