What is the ruling on greeting by gesturing without uttering the salutation, especially while driving a car?

The prohibition of greeting with a gesture is for a tanzīhī dislike (dislike that does not reach the level of prohibition) according to the majority of scholars, except in cases of necessity, such as for a person praying, a deaf person, or when a mute person gives and returns a greeting, or when combining a gesture with the verbal utterance. Some scholars view the restriction to only a gesture in greeting as prohibited.