Item from July 14, 1992, in China Daily: Spraying and scrubbing, the private car-washing business is mushrooming in the coastal cities of Fujian province.

Most carwashes are family owned. They charge 5 yuan to wash a car and 2 yuan for a motorcycle.

The carwash industry has enjoyed rapid growth since China raced past the United States to become the world's largest auto market in 2009.

Last year, more than 28 million vehicles were sold in the country, up by almost 14 percent from 2015.

The boom in the auto industry has resulted in the expansion of car-washing services across China. Annual revenues are expected to top 25 billion yuan ($3.7 billion) by 2020, according to industry estimates.

Given the growing role smartphones play in everyday life, apps providing on-demand car-cleaning services have been popular among motorists.

Instead of going to a traditional carwash, owners can use online booking or a mobile app to order cheap labor armed with sponges and soap, direct to their driveway.

Guagua Xiche, one such app, offers washes for as little as 29 yuan.

In the wake of the boom in the sector, many cities have issued regulations to conserve water and protect the environment.

In Beijing, companies engaged in the carwash industry are required to use recycled water. Violators could face fines of up to 20,000 yuan.