Like a ringtone for your car

So you’ve bought a new Ford Mustang and you want to hear a perfect deep-throated roar as you punch the gas and pull away from that Chevy Camaro. There’s an app for that.
 
Roush Performance’s Active Exhaust lets an Apple iPhone or iPad customize a Mustang’s sound and save the settings on those devices. It’s available for 2015 Mustangs with Roush’s Quad Tip exhaust system.
 
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The system comes with three preloaded exhaust modes as well as the ability to create a custom sound. Touring is a quieter setting for neighborhood cruising. Sport is louder at lower speeds and less noisy in normal city driving. Track, for off-street use, bypasses the muffler for a full, unrestricted tone.
 

When I first read the headline, I thought Ford was making an all-electric Mustang, and that the engine noise would be synthetic. Electric cars are so quiet some think it's a safety problem as pedestrians, cyclists, and even other drivers often can't hear them approaching.