Seems quite expensive, might try this:
http://www.amazon.co...3SJC6BF7CG07J0F
A little goes a loooong way with this stuff. And don't just do headlights, do any exposed plastic.
Black plastic under wing mirrors, plastic sill plates, engine bay plastics, B-pillar plastics, etc.
C4 is the same stuff as C1 and C5, so it will also do bodywork and wheels too. Basically every exterior surface on the car except glass.
Just my luck, the only gtechnic product I have left is the glass one ( not gtechnic fan, overpriced and over hyped imo )