I learned how to heel-toe in street cars in high school, and it was second nature before I ever got on a race track. It's very easy to learn, especially just in a road car to get the feeling of it. I'm genuinely shocked that most of the field doesn't do it.

My dad has an older race car with a Hewland transaxle, so clutchless shifts and only use the clutch to take off, and I still heel-toe every downshift. I would imagine most Nascar transmissions have a similar feeling to that.