Checking for a tag via OnTriggerEnter doesn't work

I have a problem with the OnTriggerEnter function.

I have a prefab which contains a model and a point light. This prefab is also a NavMeshAgent. I set the tag of this prefab to car. I then had a box which has the “IsTrigger” property checked. The box collider I have a script attached with the following:

 private void OnTriggerEnter (Collider other) {

        if (other.tag == "Car")
        {
            Debug.Log("Car entered");
         }

        if (other.tag == "Player")
        {
            Debug.Log("Player entered ");
        }
    }

When the Car prefab enters moves into the box collider, the debug message does not execute. However, if the FPSController (which is assigned the Player tag), I get the debug message. I thought that the problem could be a conflict of collision boxes within the Car prefab, so I disabled everything except the box collider, and I made sure to uncheck the “IsTrigger” property on the car. I still do not get any debug messages. is there a problem with using trigger boxes with NavMeshAgents?

Derp, I figured it out again. It turns out that the reason why car tag was not being detected was because there was not rigidbody component. I didn’t add it in because I didn’t want gravity (I forgot that I could disable gravity for each rigidbody).