The manufacturers of bodies and trailers in Europe are mainly composed of small and medium-sized companies with limited financial and human resources. Therefore, any future CO2 certification must take these concerns into account. A CO2 certification for bodies and trailers must avoid additional bureaucratic or financial burdens for manufacturers, especially since the wide variety of bodies and trailers is tailored to the specific needs of customers. For example, the number of vehicles produced per body type is often very small. Cost and labor-intensive procedures for generating specific CO2 values for these vehicles are thus not economically feasible in many cases.

Against this background, the EU Commission is developing a proposal that focuses mainly on the certification of closed body types and trailers in the O3 and O4 categories with closed bodies (box, radiator, curtain-side). Other body types (silo, open box, tipping body, tank, etc.) are initially not to be included in any CO2 certification.