Is the road down to the glo worm caves near lithgo 4wd Only? ?

i seem to remember going there in a really old school corolla and i have read recent blogs and they all say that the road is really really narrow and is filled with huge potholes and mud and dirt that no one would atttemp this in a 2wd car. the road is Glo worm tunnel road and that leads on to old coach road .I havea farily new holden commodore and i have taken that were many 4wd owners wouldn't go. so i'm not that afraid . can anyone shed some light on this ? i belive its in wollemi national park