The EX model adds a power moonroof, 4-wheel disc brakes, 16-inch alloy wheels, an additional 12-volt accessory outlet ( for a total of two ), a 350 watt stereo system with six speakers ( coupe only, the sedan EX comes with a 160 watt stereo system ), exterior temperature indicator, a foldable rear arm rest with integrated cupholders ( sedan only ), and an optional voice-activated navigation system.