mechanical and electronic driving aids for physically disabled persons, namely, hand controls for steering, braking and acceleration of motor vehicles; hand controls for operating secondary functions of vehicles such as lights, heat, air conditioning, radios, and windshield wipers; extensions for accelerator, brake and clutch pedals for use with and without platforms; left foot accelerator pedals; steering knobs; power transfer seats for wheelchair users; wheelchair lifts and ramps for vehicle ingress and egress; seats for motor vehicles