Having a hard time figuring out what light bulb you need to replace a burnt out bulb? Or are you looking to replace those dull factory exterior & interior bulbs. You are in luck, we have compiled a list of interior and exterior bulb types and socket sizes for your 1999-04 Mustang. In this guide you will find everything you need to replace your Mustang's factory light bulbs. We will cover everything from LED and OE Replacement!