Eighty years ago this month, the September 1937 issue of Radio Craft shows this idea to combine a public address amplifier and radio to “produce a useful adjunct to itinerant groups.” The tour guide, who may either be the driver of the lead vehicle or in the side car, can augment “the pleasures of a jaunt through the countryside” by serving as a “guide well acquainted with the route.”  Judging from the cover photo, it appears that having the tour guide in the side car would be a better idea, so that the driver could keep his eyes on the road.

Between pointing out points of interest, he could flip a simple two-way switch to play the radio. The same idea could be used for groups of motorcyclists, but this would require “a power amplifier with somewhat higher output in order to overcome the increased noise level.”

According to the magazine, “it seems rather odd that no one has thought to put this idea into practice.”