The high-pitched squeaks coming out of your four-banger Toyota Corolla impress no one, but download an iPod app that uses the accelerometer to make your car sound like a supercar and at the very least you'll amuse a few people.

The app is called Instant Supercar; it costs $2.99 and has the ability to mimic the sound of everything from an Audi S5 to a Bugatti Veyron. It even matches engine noise to your car's speed. We're totally dialing up a Nissan GT-R the next time we're on a roller coaster. [InstantSuperCar via Autopia]