We successfully ran a 18.2 million cell CFD case on our newest GT model, which includes the engine, gearbox, differential, shafts etc. This is the closest detail level to a production car we will be running CFD calculations on.
The finer mesh seems to have improved the quality of the results since the calculation converged much sooner with the finer mesh.
Downforce: 5431N
Drag: 1101.8N