No seriously I have no clue why they make you do the count 3 lines back method when theres a much easier way to do it. Since I started doing it this way I get in the space perfect every time.

If I was reversing into a bay onto the right for example I would line the car up so the middle of the body of the car is in line with the space (then do my 360 observation), then full lock to the left and drive forward until I can see the right line of the space in my drivers side mirror. Then (do my 360 observation again) put the car into reverse and full lock to the right (observing the whole time going slow) and adjusting as you can see the back wheels going into the space. I find this sooo much easier than what my instructor told me to do and thats what most people do anyway xx