If you know these things then you'll know that a car auto transmission
is just a cut down locomotive hydraulic transmission. Further you
don't need to heat fuel all the time you are stationary, just before you
need to start up in the morning.

Which car has a Mechydro system (eg Hymek), which car has multiple torque
converters (eg Voith - Western)?

Perhaps Honda should use them!!!!!!

I think some shunters - eg 03 have epicyclic boxes but are manual. The old
DMUs have manual epicyclic supposed to take 7 seconds to change gear - I
have been on one where they power shifted.