I use Rigacar plugin. MacOs Ventura, Blender 3.4.1 (Steam)
At first I parent everything to the body of the car, origins to geometry and finally, apply all transformations.
However when: Add > Armature > Car (Deformation Rig)
The whole model rotates on it's side and scales from around 5 meters of length to 200 meters length of the car.
Next happens
The model is imported using SketchFab Add-On in Blender from URL:
The lightning is not in the model and is added by myself.
Rotational Beacons are separated from the lightbar and rotate.
https://bayfiles.com/v0Icp5Y6y8/police_car_blend (close all pop-ups)
Z axis facing rig as mentioned in comment below an answer. Is it because of the ground not set??