8.—(1) For the purposes of this Part of these Regulations, an exempt tyre is a tyre which falls within any of the descriptions set out below—
(a)a bias-belted tyre or a diagonal-ply tyre, being a tyre designed for fitting to a wheel of a motor vehicle or trailer manufactured before 1st January 1949;
(b)a tyre constructed solely for use off roads and bearing words or letters which indicate that use and which were moulded on to or into the tyre at the time of manufacture;
(c)a tyre constructed solely for use on vehicles in competitions and bearing words or letters which indicate that use and which were moulded on to or into the tyre at the time of manufacture;
(d)a tyre bearing one of the following tyre-size designations namely: 185R16, 125R400, 135R400, 145R400, 155R400, 165R400, 175R400 or 185R400, being a mark that was moulded on to or into the tyre at the time of manufacture;
(e)a tyre designed primarily for fitting to a wheel of a vehicle manufactured before 1st January 1933.
(2) For the purposes of this Part of these Regulations, a tyre is supplied in exempt circumstances if—
(a)the tyre is constructed solely for use on a vehicle for the purposes of tests or trials of the tyre, and
(b)the supply is other than in the course of a retail trade or business,
or if the supply of the tyre is by a person who reasonably believes that the tyre will not be used in the United Kingdom.