I remember these vehicles as a kid. I grew up in the city in the 40's. Most working families only had one car (if that) but the man of the house used it to go to work. They were decked out as a rolling store. Primarily vegetables but also carried bread and other necessities. They would cruise up & down neighborhood streets (much as the ice cream truck did). They would stop in each block & the ladies would go out & buy their supplies.
Remember the milk man & his truck from the same period.
The GOOD OLE DAYS.
Harold