Hi Demon,
I hope you all can consider marking the outside of the course with something less damaging than the water-filled plastic barriers, especially on the faster turns, which, in Shah Alam's case, is the 1st turn. From what I see, it's doing more damage than good.
I think majority of the drifters would like to have more margin for errors ie. some run-off after going off-track before hitting something. Impact sponges do a great job stopping cars without damaging them too much.