You know where Everland is? The amusement park? The racetrack there is where virtually every Korean race series takes place. The two main ones are the KGTC (sponsors, no forced induction), and the DDGT series, which is multi-discipline (drag, drift, time attack, GT circuit, no restrictions on forced induction but weight penalties for drivetrain - 800kg for FWD, 1400kg for AWD). The DDGT looks FAR more interesting and of course you've got to have well-rounded skills and a swiss-army knife of a car to win the championship, but the people who run it are non-sponsored amateurs and you see a lot of cars blow up their engines during the drag runs and the circuit race
Regular people can run the circuit, I think it's 30,000won for 30 minutes track time. The track itself is very similar in length to Tsukuba. You need to attend a safety class (3 hours), have a four-point harness and a large fire extinguisher in your car. I don't know where to take the safety class though, but if I find out, we should take it together - I'd rather go with fellow english speakers than be the odd-man out as usual, with my non-functional Korean.