Bryan,
The pictures are a big help, thanks.
It appears that you still have the glow effect applied to the comp, which will break the 3D rendering order in AE (After Effects). The result of this is that your 3D pre-comp (Road/road_course) is no longer a part of the main comp’s 3D space, but instead is rendered and flattened and the effect is then applied. So essentially, your 3D pre-comp is a flat movie of your pre-composed layers.
Try applying the glow effect to the pre-composed layer(s) inside the pre-comp and removing the effect from the pre-comp itself. If you need the glow to be applied to multiple layers in your pre-comp then apply it to each of the layers that require the effect individually. Don’t use an adjustment layer or you’ll have the same problem as it will also break the 3D rendering order (I don’t know why, but it does).
The 3D switch does not need to be selected on your pre-comp but the “collapse transformations” switch does. Also, you will get very different results depending on whether your pre-composed layers have their “collapse transformations” switch turned on or not. Try it and see.
I hope this helps. Believe me, I pulled out my hair trying to figure this stuff out before.
I would have included pictures but I don’t know how to post them here.
-E