Please be advised that the ADR's are not specific vehicle identified. A vehicle must meet all the ADR requirements if it is ADR applicable. Some vehicles may be exempt.It is the owners responsibility to maintain a vehicle in ADR requirements, as governed by the federal and state road authorities. That is one reason that people get pulled up or have regular roadworthy inspections.To get a better understanding of regulations etc it may be more informative for you to speak to someone from your state transport authority. As for the parts themselves it is often people modifying vehicles that look at what they can interchange and make those decisions.