Ok, so for the first simulation called “Check” with “Course” mesh , the simulation has no issues and runs is OK ( runs on all parts ).
The Boundary Conditions you have used in this simulation ( check run settings) were correct. But you did not assign any boundary condition to the car e.g ‘no-slip wall’. It is by default done also, but is always better to do it yourself.
[ By the way the “Course” mesh has also cells inside the car, this happens sometimes for course meshes as the geometry can not be fully resolved. But its not a big issue and making a fine mesh will solve this.]
Regarding the result you were seeing, it was just a small bug in the auto post-processing . This I have fixed and checked locally. The result for you first case “Check” now looks like below:
This fix has to go through some more testing before we can put it online with the next release. So in the mean time you can use the online Post-processor or do it locally on Paraview.
I will let you know when the fix is online. ok