For the 2013 Volkswagen GTI, the low-beam headlight uses a D1S bulb. High-beam fitment is listed as either H15 or D1S, so verify the headlight assembly before ordering. Daytime running light fitment follows the headlight type: H15 with halogen headlights and LED with HID headlights.
Rear lighting varies with the tail-light configuration. GTIs with LED tail lights use LED bulbs for the brake and tail-light functions, while versions without LED tail lights use 921 bulbs for both. The reverse light is 921 with LED tail lights and 7440 without LED tail lights. The rear turn signal uses a 7440A bulb, and the center stop light is LED.
Other listed fitments include 2825 or 98 for the license-plate, parking, and map lights; 2821 for the front side marker, step, courtesy, and glove-box lights; and 6418 for the dome and vanity lights. Trunk-light fitment is listed as 6411 or 6428.