OK, getting closer here. For this version, I rebuilt the track from scratch due to issues with the original where cars "fall through the surface". I believe that's completely eliminated in this version.
At the same time, I reworked the track for smoothness and cut out the higher speed sections. The track is now only about 4300m and I think is much more suitable for touring cars, etc.
One note - this track has very little camber, so I'd say as a result you really need to get speed down before entering a turn. I set it this way because I think it puts more onus on drivers to drive the track. If you prefer the track with camber let me know and I could put some in. I look at camber as kind of a mini form of banking (IOTW a driver's aid) - maybe that's unfair or just wrong, you be the judge.
The major things still missing are collision borders, pit lane speed, and cameras. I don't know how to restrict pit lane speed yet, but the borders and cameras I think I'll have ready within a couple of days.
AI is working though I didn't test them pitting yet, and there seems to be a spawn problem with car 1 & 2 as AC drops one on the other before a race starts, though it doesn't much impact the race itself. There's also some minor fixes with the pits to be done, should be out soon.
I think this RTB proof of concept is starting to look like it will make it with no other tools. Let me know what you think with some feedback. Thanks!