Below is a list of light bulb types used in 2002-2010 AUDI A8 lighting system, covering saloon 4-door vehicles.
Headlight bulb: low beam - H7 or D2S / high beam - H7 or D2S
Parking light bulb: W5W
Fog light bulb: H7 or H11
Additional high beam headlamp bulb: H7
Daytime running light bulb: P21W
Cornering light bulb: H8
Back-up light bulb: W16W
Rear fog light bulb: W16W
License plate light bulb: C5W
Door light bulb: W5W
Door safety light bulb: W5W
Boot light bulb: W5W
Entry light bulb: W5W
Footwell light bulb: W5W
Glove compartment light bulb: W5W
Light bulb sizes for other AUDI A8 generations: A8 (4D) / A8 (4H)