When Audi entered the Indian market, they had to create a new car horn to withstand heavy use by Indian drivers
Audi launched the Audi TT Coupe in India in 2012. They soon found they needed to tweak the horn a bit. According to the director of Audi India, drivers in Mumbai use their horns as much in one week as a German driver might in one year. That's how crazy Mumbai traffic is.
So Audi gives it's Indian cars a different horn. To start, these horns are tested for two weeks continuously. They also have different settings and are supplied by different companies than regular Audi horns. The Indian Audi horns are also much louder than regular ones.
Horns in India are used to signal many different emotions, not just anger. One study found that there is one horn honk every three seconds at major intersections in Calcutta.
Audi says they are very popular with Bollywood too, particularly their Q7 model. And members of that community have spread the word about Audi in the country.