The underframe of a motor vehicle seat is equipped with weight sensors for sensing a weight load on the motor vehicle seat. The weight sensors are interposed between a first structure part, such as a seat profile of a longitudinal guide, and a second structure part, such as a console or a seat shell, and sense the weight exerted through the second structure part on the first structure part. The weight sensors are fastened to the first structure part and comprise sensor bolts projecting upward. Holes for the sensor bolts are provided in the second structure part. The sensor bolts extend through the holes and one nut, which forms a surrounding grip around the holes, is associated with each of the sensor bolts. The holes of the second structure part each comprise one hole region that surrounds the holes and is configured as a cap.