That is a good analogy, but I would like to point out that traditional automotive manual transmissions do not use planetary gear architecture, they use a mainshaft and countershaft design. Traditional automotive automatic transmissions actually use planetary gearsets very similar to a bicycle IGH. I believe the planetary configuration has the advantage that the physical shifting mechanism can be much simpler to implement via a cable or hydraulics. The recent trend for automotive automatic transmissions, however, has been to automate the mainshaft & countershaft design. Why? Two reasons, 1), because this design is inherenly lighter and more compact for the same combination of range, # of ratios, and torque capacity than a planetary design, and 2), because it has inherenty lower frictional losses than a planetary design (for a mainshaft/countershaft design in any non 1:1 forward gear, there are a maximum of two pairs of gears in mesh. I believe the planetary automatics also have appreciable windage losses from the bands and clutchpacks that are not engaged in a given gear).