Volkswagen is the brand name for a line of automobiles originally produced in Germany. Though the company is still headquartered in Germany, Volkswagens are now manufactured and assembled in many countries, including the United States. According to the Wall Street Journal, Volkswagen held a 2.3 percent share of the US motor vehicle market in 2010. The iconic Volkswagen Beetle, with its engine located in the rear of the car and trunk in the front, remains popular and widely available even though production ceased in 2003.
The company got in trouble in the 21st century when some of its diesel cars were discovered to have been designed to cheat on emissions tests.
- VW’s “defeat device” is not a physical device but a programme in the engine software that lets the car perceive if it is being driven under test conditions - and only then pull out all the anti-pollution stops. “Clean diesel” engines cut emissions through techniques such as adjusting air-fuel ratios and exhaust flows, and in some (though not most VWs) injecting a urea-based solution to render NOx harmless. When running normally, requiring greater performance, VW’s controls would not operate in the same way. 
- Volkswagen admitted in 2015 that it rigged nearly 600,000 diesel-powered cars sold in the U.S. to cheat on emissions tests.
Brands which are manufacturerd by Volkswagen:
- The Volkswagen emissions scandal explained - The Guardian, 23 September 2015
- FBI Arrests Volkswagen Executive in Emissions Scandal