May 13: On this day in 1946, the Federal Communications Commission (FCC) granted Southwestern Bell a license for radio-telephone service, which enabled those in St. Louis to be the first in the nation to make and receive phone calls in their car.
Covering a 75-mile radius of downtown calls to an auto had to be placed through a mobile operator at 2654 Locust. This was transferred over normal telephone lines to the office at 1010 Pine, where the call went out over VHF radio from the 250-Watt transmitter on the building’s roof.
Service cost $15 a month, after a $25 installation fee. There was an additional charge per call, depending on time. As seen in this photo, necessary equipment took much of the trunk space. The first radiotelephone call was placed in St. Louis on Jun 17, 1946.
Source: John Sarkis & Missouri Life