https://assets.publishing.service.go...e-guidance.pdf
In addition if a vehicle (including a motorcycle):
• has been issued with a registration number with a ‘Q’ prefix; or
• is a kit car assembled from components from different makes and model of
vehicle; or
• is a reconstructed classic vehicle as defined by DVLA guidance; or
• is a kit conversion, where a kit of new parts is added to an existing vehicle, or
old parts are added to a kit of a manufactured body, chassis or monocoque bodyshell changing the general appearance of the vehicle;
it will be considered to have been substantially changed and will not be exempt from MOT testing.