Small project I'm working on has actually yielded something interesting and unexpected this evening. I've been updating my track tags with the real FIA grading that applies to them and searching for missing tracks as I went along. Came across a South Korean circuit I'd not heard of before (FIA Grade 2) called Inje Speedium which was opened in 2013. Did some searching and found a ton of videos of people lapping it on Assetto Corsa on YouTube, but the mod itself seemed to be a ghost, with no mention on any site or source for AC that I could find.
However, I'm pleased to say that after more than an hour playing around with translators and searching the darkest reaches of the South Korean internet, I was successful in my search. Unfortunately due to clearing browser history upon closure, I've absolutely no idea which selection of Korean symbols lead me finally to my goal so I can't provide the original source.
Still, here is the track, which seems of reasonable enough quality - AI, track cameras, 31 pitboxes and no errors when loading and driving.
https://mega.nz/#!yo93HKjL!Bscp6UIhM-1ptarRbDxz8_S_yZ2CEFslqh2yrI0dqKU
I suspect that unless I suffered some kind of brain haemorrhage in the last few hours and missed an obvious link, this is the first time this has been released to English speaking players. No idea who the author is, so credit goes to the South Korean AC community as a whole! Enjoy!