Is it permissible to have a special division from the car, imposed by its owner in exchange for its use in collecting permissible items for sale, in addition to the original division of the proceeds among the participants?

It is permissible to jointly go out to the desert and gather permissible things such as firewood, grass, and fruits. This type of partnership is called "Sharikat al-Abdan" (partnership of bodies/labor). The proceeds are divided among the partners according to their agreement, either equally or unequally. It is permissible for the owner of the vehicle to stipipulate an increase for himself over his partners.