Damn, I’ve been trying to get good at this skill, and it’s been tough. I think that tip about body posture and positioning is going to make it all smooth for me. Especially with cars, it’s like the Doppler effect, they whiz by so fast I can’t twist my body fast enough to match their speed , because they are moving faster relative to my position when they get closer. That’s such a great idea to compensate for that.
on the far ends, it's definitely easier with less finesse necessary to match the speed/angle. I agree though, just get the technique down and dont let anything get in the way. I also find it much easier on smaller setup, or on a tripod with a good rotating mount