To create a rig, make sure to follow these steps before exporting:
• Your car should be facing the positive X axis, and its pivot point should be centered at the origin of the scene.
• The front wheels should have their pivot points centered within the wheels but offset slightly into the body to allow proper rotation.
• The rear wheels should also have their pivot points centered, but without any offset.
• Make sure to reset all transforms for the car and the wheels. In Blender, select the car and the wheels, then press Ctrl + A and apply all transforms.
• In the export settings, make sure the axis is set to X Forward and Z Up (this is the correct setting in Blender, if I remember correctly).
• You should also export a skeletal mesh. When importing into Unreal, make sure Import Skeletal Mesh is checked.
For the skeletal mesh setup, check this video:
