How to (properly) backwards drift in this game?

Every time I try to do it, I bump into obstacles or go offroad

Honestly..I don't know, as I haven't really invested much time into reverse driving, but I'll look into it.

yes, JPG's video is very useful and I highly recommend checking it out

RD is basically just super mini turbo (orange mt) spamming, it isn't too difficult to get a hang of