The Race Commentator/Narrator.
The Race Commentator is an unseen character in the Wacky Races. He was voiced originally by Dave Willock.
Every episode was introduced and ended by the Race Commentator, and in the US two episode series he would do the 'Interlude' part as well. He would often talk to the drivers, who would answer back looking at the camera.
The role of the commentator was taken over in the Wacky Races reboot by the character of Brick Crashman.