If you want to see how it works, and the engine, etc, Jay Leno owns one: Jay Lenos Garage- CORD
But basically its not as weird as you think. Just a series of electrical motors that automate the process. It seems redundant today, but people really didn't like shifting back then. Thats why cars like the Model-T used a primitive automatic trans instead of a traditional manual.
As for the most complicated 30s era car? Maybe the Doble Steam car. Literally "steampunk" with dials, and valves everywhere.