Regarding the certificates that the manufacturer issues on behalf, of the NCC, they only document fulfilment of certain industry standards, primarily with regard to habitation equipment. They do not certify fulfilment of road vehicle construction and use regulations as that is the job of the Vehicle Certification Agency as the official type approval authority. Type approval, on the other hand, does not get involved with things like flammability of upholstery, gas supply, electrical safety of habitation equipment, etc. because these are not relevant to road safety. It is unfortunate that the NCC seems to be poking its nose into road legalities as well instead of concentrating on things that are not covered by vehicle type approval. What is worse is that they convey an impression of having the authority of a legislative body.