It's a step to make it easier to get into the car, especially for women in long
skirts. Like many items on early cars, they were inherited from horse-drawn
carriages, which rode very high. Most cars designed after WW II did not have
them. The VW you mentioned was designed well before the war.

George Patterson
     Forgive your enemies. But always remember who they are.

running boards were a carry over from the horse. As wheels were BIG a
way was needed to step up into the conveyance.  Footmen or Livery men
had a foot step to start people on their way into the ride. By the
late 1850's the step was built in. A " RUNNING BOARD "  that went with
the unit.They were used until the early 40's . A '39  car from most
producers had a " running board " not unlike that of the VW.  Just a
trim chunk of rubber to keep the old folks happy.

Now my '35 Buick has real running boards. Which we have found makes a
HUGE difference when we take the " GIRLS "  82-91 in age , for a ride
in it to get ice cream.

Steven E.

There is some that claim that firefighters invented running boards.  In the early days volunteers would chase the fire apparatus to
the fire, sometimes arriving very tired.  Along came the idea of mounting boards along the sides of the apparatus allowing the
firefighters to run out to the rig and climb aboard.

It might not be true but it sure makes a good story.