Select [Recording] on Volume Control Properties to set the level of the microphone a little lower.
The internal microphone is a non-directional microphone. Therefore, it also records noises around you. In addition, the input level of the microphone is set a little higher by default. To improve the situation, select [Option] -> [Property] on [Volume Control], and select [Adjust volume for] -> [Recording], and then set the sound volume of the microphone a little lower.
This makes the level of conversation volume lower, however, the background noise is reduced fairly. The level of noise varies from one person to another. Since the driving noise cannot disappear completely, noises contained in the sound cannot be removed completely.