Abstract: Wheelchair designs and enhancements are provided for use with conventional wheelchair designs. The designs and enhancements include first and second contoured folding seat panels that are hingedly mounted with respect to the wheelchair frame and that are offer interlocking functionality. The folding seats generally provide contouring in both front-to-back and side-to-side directions. Features are provided to prevent capture of objects between seat panels as they are brought into interlocking engagement. Pivotal footrests that offer enhanced stability in the form of lateral, front-to-back and up-down stability are provided In addition, axle and axle plate combinations are described that provide enhanced flexibility in relative positioning with respect to the wheelchair frame. The disclosed features and functionalities may be incorporated into wheelchair designs, either in whole or in part, to provide enhanced user interaction with the wheelchair.