Possible error in Cd value

Good morning everyone,

I am working on a research project to improve the aerodynamics of a land rover defender 110. In doing so, I am simulating with different concepts. Now simulating the baseline has gone well. Now I have only created my new concepts from which I have simulated two models in SimScale. One model here has a flat floor and the other has optimised wheel arches. The expectation of this was, of course, that the Cd values would be lower, but they turned out to be higher. Now I just have my doubts about the reliability because new low airspeed areas have appeared in the four corners of the wind tunnel (see appendix). In my opinion, this is not quite right, but I don’t know where the error lies because the settings are exactly the same as those of the simulation of the baseline model, which had gone well. In addition, the mesh at these four corners also looks good.

![image|690x432 (upload://7EXgOUG23YAy9ZT3hj6cFX7rW5a.jpeg)

Here my Project link of the new concept: SimScale
Here my Project link of the Baseline model: