Unfortunately in this particular use case, switching off instancing engine doesn't work. I think that has to do with how I'm randomizing the paint colors, and when the RC object is converted to geometry for the cloud, it is assigned the random material ID to the entire mesh. Which is why I get the right paint color scattered, but the entire car is just paint color.
Not having RC or Forest color going forward into the cloud is going to be a hurdle for us, but I understand that's how Chaos Cloud works. It's not Max + Vray, it's Vray standalone and that doesn't have full support to more of the Max-centric features. There may be a few more things I can test for this case to see if there is a work around.
For 99% of the other uses of RC and FP, going to the cloud has been pretty seamless. Parking lots on the other hand, that's a bit of a head scratcher.