A long rail assembly for transposing a vehicle seat along a long rail, the long rail assembly comprising: a fixed long rail having an elongated frame with a generally U-shaped cross-section in profile, including a bottom wall, a top wall, opposing first and second side walls (98, 100) (60, 64), an interior cavity, each side wall (60, 64) including a generally C-shaped cross-section in profile forming a track, each track (80, 82) having a track bottom wall (80A, 82A), a track side wall (60A, 64A), and a track top wall (86, 88), and the fixed long rail having an elongated opening extending longitudinally in the top wall; and a rail drive assembly configured to be repositionable along the interior cavity of the fixed long rail, the rail drive assembly comprising: an elongated main body having a generally inverted U-shaped cross-section in profile, the main body having opposing first and second side walls (98, 100) and a third wall extending between the first and second side walls (98, 100); front and rear axles extending laterally though the first and second side walls (98, 100), each of the front and rear axles having opposing first and second axle ends; a wheel fixedly coupled to each axle end of the front and rear axles and configured to travel down respective tracks in the long rail; and at least one stability rolling element (181, 182) operatively coupled to one of the first and second side walls (98, 100) of the main body, characterized in that the at least one stability rolling element (181, 182) is spring-loaded to frictionally engage with the long rail on one or more of the top wall, the side wall, and/or a curved portion extending between the top wall and the side wall of the long rail. a fixed long rail having an elongated frame with a generally U-shaped cross-section in profile, including a bottom wall, a top wall, opposing first and second side walls (98, 100) (60, 64), an interior cavity, each side wall (60, 64) including a generally C-shaped cross-section in profile forming a track, each track (80, 82) having a track bottom wall (80A, 82A), a track side wall (60A, 64A), and a track top wall (86, 88), and the fixed long rail having an elongated opening extending longitudinally in the top wall; and a rail drive assembly configured to be repositionable along the interior cavity of the fixed long rail, the rail drive assembly comprising: an elongated main body having a generally inverted U-shaped cross-section in profile, the main body having opposing first and second side walls (98, 100) and a third wall extending between the first and second side walls (98, 100); front and rear axles extending laterally though the first and second side walls (98, 100), each of the front and rear axles having opposing first and second axle ends; a wheel fixedly coupled to each axle end of the front and rear axles and configured to travel down respective tracks in the long rail; and at least one stability rolling element (181, 182) operatively coupled to one of the first and second side walls (98, 100) of the main body, characterized in that the at least one stability rolling element (181, 182) is spring-loaded to frictionally engage with the long rail on one or more of the top wall, the side wall, and/or a curved portion extending between the top wall and the side wall of the long rail. an elongated main body having a generally inverted U-shaped cross-section in profile, the main body having opposing first and second side walls (98, 100) and a third wall extending between the first and second side walls (98, 100); front and rear axles extending laterally though the first and second side walls (98, 100), each of the front and rear axles having opposing first and second axle ends; a wheel fixedly coupled to each axle end of the front and rear axles and configured to travel down respective tracks in the long rail; and at least one stability rolling element (181, 182) operatively coupled to one of the first and second side walls (98, 100) of the main body, characterized in that the at least one stability rolling element (181, 182) is spring-loaded to frictionally engage with the long rail on one or more of the top wall, the side wall, and/or a curved portion extending between the top wall and the side wall of the long rail.