Below is a list of light bulb types used in 2004-2012 MERCEDES-BENZ A-CLASS lighting system, covering hatchback vehicles.
Headlight bulb: low beam - H7 or D2S / high beam - H7 or D2S
Parking light bulb: W5W
Fog light bulb: H11
Front indicator/turn signal bulb: PY21W
Cornering light bulb: H7
Rear indicator/turn signal bulb: PY21W
Tail light bulb: P21/4W or P21W
Brake light bulb: P21W
Back-up light bulb: P21W
Rear fog light bulb: P21/4W or P21W
License plate light bulb: C5W
Interior light bulb: C10W
Boot light bulb: C10W
Footwell light bulb: C5W
Reading light bulb: W5W or H6W
Glove compartment light bulb: C5W
Light bulb sizes for other MERCEDES-BENZ A-CLASS generations: A-CLASS (W176) / A-CLASS (W177)