A grain cart has a wheel supported frame on which is mounted an open top container having inclined bottom walls and including a discharge auger conveyor having a lower section extending from a sump for the container adjacent a front left inclined corner portion of the container. The whole procedures are established under a base concept of secondary template. Hereby may be achieved provision of a tool-free assembly method for the sectional rail system and that by screwing on plate covering close to the edge part of the intermediate rail, it is avoided that the screw web and the associated reinforcement web \u201ccapsize\u201d.