The number of passengers permitted in your vehicle depends not only on the number of belt positions available but also on the actual remaining load reserve, i.e. the difference between the permissible total mass and the actual mass of the vehicle.
It may be that the permissible number of persons changes as a result of adding or removing weight, or that it is not possible to remove weight at all. As the mass of motorhomes can change due to add-ons, conversions and repairs, among other things, the permitted number of passengers must always be recalculated after weighing by an expert, taking into account the relevant standards and applicable legislation, and confirmed for entry in the vehicle documents if the weight variant is subsequently changed.