I’ve written a few articles on undestanding rally pacenotes for Jalopnik, but Hyundai WRC drivers Hayden Paddon and John Kennard are much more qualified to cover this subject. The cover the system they use, how they make the notes and why they are so effective.
The numbers on the wheel are pretty interesting. They determine the degree of the corner based on how much the driver turns the wheel to get through the corner. Enough of me, just watch the video. Its good.
Hayden is pretty cool. If you want to know more, you can learn all about Hayden Paddon on his website.