Related Clues:

• Reacted like a taxi driver?
• Reacted to slow traffic, perhaps
• Reacted to a traffic tie-up
• Hit the horn
• Tooted the car horn
• Heeded a bumper sticker request
• Sounded like a goose
• Gave a toot
• Spoke like Harpo Marx?
• Tooted
• Used a horn
• Pushed the horn
• Horned in?
• Tooted one's horn
• Made Jaguar noises