Published by OneSwitch.org.uk Wednesday, 5 April 2017 8:38 pm.
The three rough and ready videos above show a slew of methods for playing a driving game with reduced controls. Top uses Microsoft's fantastic Xbox One Co-pilot feature, not so much for team play but to combine a standard wireless controller, using just the left-stick, with a custom accessibility set-up.
The second video shows a two-switch method for driving. This might be one head switch and one "shout box".
The bottom video shows a one-switch method of driving. This requires the auto-scanning "One Switch Pulse" system to be active. Three fast taps cycles between go fast / drift / reverse / drift. Otherwise the switch controls alternate steering left / right.