http://www.betawired.com/ford-mustang-ecoboost-fakes-engine-noise-for-distinctive-sound/144977/
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Once known as one of the greatest American muscle cars, the Ford Mustang has fallen from grace: it was recently revealed that the 2015 EcoBoost model of the Mustang actually pipes in engine sounds in through the car's speakers.
The Mustang comes from a venerable line of pony cars, and was a direct competitor with Chevrolet's Camaro and now-defunct Firebird muscle car models for decades. However, due to new emissions standards and more Draconian fuel economy requirements modern vehicles can't boast the same size engines as in yesteryear - and the full-throated V8 engines of the muscle cars of the 1970s have been replaced instead with turbocharged four-cylinder engines instead.