I've been watching this forum for a while, waiting for the update and now that I have something that works it's quite exciting! Now that I have something to offer besides the praise so many others have voiced, I thought I would share my experience in using the new v13 RHW on the Mac.
It took me a couple of tries to install it so that the textures would be rendered correctly, but this seems to work (along with pathing). I grabbed a screenshot of my folder so others could duplicate this easily. This is in my Applications/Sim City 4/Sim City 4 Data/Plugins folder.
Keep up the good work! Can't wait for the new interchanges....
And Tarkus, thanks for the imageshack tip.