I bet you hadn't heard this before... the REO Speed Wagon, was built to cash in on business delivery uses, and Coca Cola was the 1st to contract for a fleet of them

on the side of the cab below the belt line is says, Coca Cola, Orange Crush, Green River.

The gas tank above the drivers knees says "Speed Wagon"

https://www.amexglobalbusinesstravel.com/100thanniversary/reo-motor-car-company-white-motor-company-coca-cola/

http://aacalibrary.tumblr.com/