All its parts are parented to the car body object for free moving and rotating, also the wheels, each wheel is parented to a unique empty for easy rotating.Model polygons: 1,541,074 with wheels and 1,389,930 without wheels.Model is available in blend, fbx, and obj.
The car is now riggid, you can move the car in Y axis and will see all wheels are rotating in x axis, i also added a steering wheel, its a right and left green arrows in the blender file, you can move the arrows in x axis to make the front wheels rotate, notice that this is first rig for me and might face some problems, i will add chassis in future and also make the rig more advanced.