This 2018 Audi A3 bulb size guide helps you verify the correct bulb type by lighting position, so you can replace the right lamp the first time. Because Audi used different lighting packages and trim combinations, the exact bulb list can vary by body style and market, but this page is organized to make fitment checks simple and fast.
Use this page to match each exterior and interior light on your 2018 Audi A3 with the correct bulb specification before you buy. It covers common locations such as headlights, tail lights, brake lights, turn signals, license plate lights, reverse lights, and cabin bulbs, including LED-equipped versions and the halogen/HID-related items where applicable.
For best results, compare the bulb chart with the equipment already installed on your car, since trim level, package content, and factory lighting options can change the fitment. Some 2018 Audi A3 models use LED lighting in many exterior positions, while others may have different headlight setups such as halogen or HID, so do not assume every A3 uses the same bulb. If you are considering an aftermarket LED conversion, make sure the bulb base, polarity, and housing clearance are compatible, and check whether the vehicle may need coding or error-free bulbs to avoid warning messages. When in doubt, remove the old bulb and verify the markings before ordering replacements.
