Wiktionary
codriver
n. The navigator in the sport of rally racing, who sits in the front passenger seat and gives directions to the driver.
Usage examples of "codriver".
Sapper Ronald Emery, on Mackay’s side of the ramp, shot the driver and codriver of the first half-track to cross.
At first I drove solo, then with a sidecar, in which I was once going along with my codriver when it so happened that a tree came exactiv between the motorcycle and the sidecar.