An excerpt from Producer Gas and the Australian Motorist by Don Bartlett
..."It is easy for the present generation of drivers, attuned to modern vehicles where electronic gadgets abound, to be ignorant of the simple facts about pre-war - and even many post-war vehicles.
Automatic transmissions were rare. Synchro-mesh gearboxes were not common either. When slowing down for an intersection or when stopping, it was usually necessary to manually adjust "the spark".
You were required by law to extend your right arm out the window and wave it up and down like a wounded albatross to warn other motorists of your intention to reduce speed.
Stop lights at the rear were optional but in effect, you were still required to signal your intention to stop, by holding your arm out the window with your elbow bent upwards to 90 degrees and the palm of your hand opened forward with the fingers, all of the fingers, pointing up.
A right-turn indication was also mandatory and was made with the unbent arm extended straight out of the window. The stop or turn signal had to be given continuously for at least 100 feet before the stop or turn.
I mention all of this, not in an attempt to be humorous but because many drivers on the road today would not have experienced that type of motoring. It needs to be understood in order to comprehend the conditions in which the gas producer system operated.
As the vehicle slowed down for the intersection, in addition to spark adjustments and hand signals, the driver had to use the left hand to make the gear shift – invariably, the gear lever was mounted on the floor.
With one hand out the window and the other on the gear shift, there was not much left to steer the vehicle – although the law said that you must have effective control of the vehicle at all times!
Meantime, your feet were moving rhythmically on the clutch and accelerator as gear changes required the now forgotten art of "double de-clutching".
Then there is the added complication of the producer gas controls. In Tibby's words, "you just played with all of the controls (choke, throttle, butterflies etc) at your disposal until you got things going OK". One contemporary report suggested that "bare feet, prehensile toes and experience at the Wurlitzer organ could be a distinct advantage".
Before entering the intersection, you had to ensure that the gas flow was adequate and, if on water injection, that the setting was appropriate for the load on the engine. Then of course, there were the other motorists going through the same ritual and approaching the same intersection.
If it was night-time and near the coast in 1942, there was the added hassle of the blackout. There were no street lights and your headlights (poor enough anyway by modern standards) had to be masked to allow only a narrow slit of light to the front.