They are synonymous with India and are the country's most common form of transport, used by everyone from schoolchildren and housewives to office workers and tourists.
But despite buzzing around the streets of virtually every village, town and city, the auto-rickshaw has not been widely exploited for its advertising potential.
At least not until now.
Three college graduates in India's financial and entertainment capital Mumbai are trying to change that and use the nippy three-wheel taxis to help sell products from financial services to cinema tickets.
The result is India's first auto-rickshaw magazine, "Meter Down", a reference to the lever on the mechanical box on the driver's cab that is pushed at the start of every journey to calculate the fare.
The first edition of the monthly, 24-page magazine came out in March, combining adverts and listings with articles on fashion and celebrities, a feature on fake goods and a look at India's growing coffee shop culture.
Some 500 drivers plying the crowded, dusty streets of Mumbai's northern suburbs have agreed to carry the free, English-language magazine for a small, undisclosed fee, with those behind it banking on a captive audience.
"The drivers say it's a nice idea if passengers are getting something to read because people get fed up in traffic jams," Mulchand Dedhia told AFP. "This helps them pass the time."
Distraction, though, is only one part of the exercise.
Dedhia, 25, and his colleagues Ishan Mehta and Simi Sailopal, both 23, conducted research that suggested that huge numbers of people in Mumbai spend 15 to 20 minutes every day in an auto-rickshaw.
"There's no other medium that can capture a passenger's attention for 15 to 20 minutes," said Dedhia.
"That gives you time to engage a brand's audience," he added.
Advertising is a rapidly growing industry in India, where liberalisation of the country's economy from the early 1990s has led to a rise in disposable incomes and a burgeoning, Western-style consumer culture in big cities.
The sector is expected to grow by 12 percent in 2010 to 246.9 billion rupees (5.2 billion dollars), according to a recent KPMG report on India's media and entertainment industry.
Television and print media currently account for the biggest share of advertising spending, with the out-of-home sector - billboards, bus shelters, pavement posters or public transport - accounting for just over six percent.
Spending on out-of-home and print advertising is projected to fall slightly by 2014 as Internet and television advertising takes off, KPMG said in the study for the Federation of Indian Chambers of Commerce and Industry (FICCI).
But the "Meter Down" trio believe that a new combination of print and out-of-home advertising could be a winning formula, complementing television and radio commercials - but targeting specific consumers at a local level.
With 160,000 registered auto-rickshaws in Mumbai alone and the city seen as a benchmark for advertisers keen to get brand exposure in the Indian market, the young entrepreneurs believe they have a sustainable business model.
"Bombay is huge," said Mehta, who like many English-speakers still uses the city's former name. "Even if you aim to tap 10 percent of the auto-rickshaws in Bombay, that in itself is quite big."
Dedhia, Mehta and Sailopal, who each contributed 25,000 rupees of their own money to get the start-up off the ground, say they are initially just trying to cover their costs.
But they plan to expand into outlying suburbs and customise auto-rickshaws with internal and external advertising well beyond existing examples such as website addresses on vehicle hoods.
Other language versions of the magazine are a possibility, as is launching across India.
Publicity has already led to enquiries from the capital, New Delhi, which has about 55,000 registered auto-rickshaws, and generated interest in the cities of Pune, Hyderabad and Bhopal, they said.
The team also believes the high-visibility scheme would work in rural areas, which have been seen as hard to reach for advertisers. Maharashtra state, of which Mumbai is the capital, has 700,000 auto-rickshaws.
"Auto-rickshaws can be a 360-degree brand solution," said Dedhia.