Below is a list of light bulb types used in 2009-2018 AUDI A8 lighting system, covering saloon 4-door vehicles.
Headlight bulb: low beam - D3S / high beam - D3S
Fog light bulb: H7
Cornering light bulb: H7
License plate light bulb: C5W
Door safety light bulb: W5W
Boot light bulb: W5W
Glove compartment light bulb: W5W
Light bulb sizes for other AUDI A8 generations: A8 (4D) / A8 (4E)