Below is a list of light bulb types used in 2013- MERCEDES-BENZ C-CLASS lighting system, covering convertible, estate, coupé and saloon 4-door vehicles.
Headlight bulb: low beam - H7 / high beam - H7
Rear indicator/turn signal bulb: P21W
Back-up light bulb: W16W
Interior light bulb: W5W
Boot light bulb: W5W
Footwell light bulb: W5W
Light bulb sizes for other MERCEDES-BENZ C-CLASS generations: C-CLASS (W203) / C-CLASS (W204)