Just like in real estate, it's all about location, location, location! Placing the microphone into the proper location made a major difference in the quality of how my voice is heard on the other end. There's a faint background sound that can be heard, but my voice is clear with no distortion or interference when driving at different speeds (with the windows closed). I did not make any effort to raise my voice or move and aim towards the microphone. I remained in my normal driving position and spoke in my normal tone and volume level. I believe the previous location was picking up air flow around the microphone which distorted everything. Thanks again for everyone's help!