Rockingham (Especially the ISSC circuit) is very fast and not very wide. Make sure time is given when overtaking. Having Race Directed and raced at the circuit myself in real life, I know how fast people come up on you especially when there is a large speed difference like we have here.
For the faster cars, just wait for a place to overtake, there aren't many on the infield. For the slower cars, make clear indication of where you are going. Mapping the indicator buttons (/press 7 8 0, (left right off)) is defiantly a good idea.
Good luck to everyone, I will try and stay out of your way.