I didn´t turn on any of the erosion control settings. I used the specifications of the Low Velocity analysis type.
I changed the car geometry: removed the wheels and the axles and I designed its body as a shell body, in order to have only shell elements in the model. It went very well because I had low simulation times (100 hrs) when compared to the previous model. Thank you for your suggestions!
I have another doubt: Is it possible to specify the mass center of the car without change the geometry? I introduced a point mass but I have to set it to rigid and when I do that, I can´t specify another constraints like displacements.