An older, less complex trailer might be adequately serviced by a workshop with the ‘Engaged’ MPRS rating, where it is acceptable that not all technicians are trained in electric or gas vehicle systems, and where specialist equipment (such as brake testers) may be accessed externally. 

However, more modern, and technically advanced vehicles – especially those powered by electric or gas systems, require a higher level of technical competence and on-site equipment. These vehicles are best served by workshops with a 'Silver’ or above MPRS rating, ensuring the necessary specialist training, tools, and infrastructure are in place to meet their specific maintenance needs.