Dull, dull headlamp bulbs.

[Mix]

Hi, I have a recurring problem with dull headlights, 2007 dci 2ltr sport. I have tried all sorts (H7s) but they are all dull. The lenses have been de-yellowed and de-scratched. Currently have phillips h7 racing vision gt200s in but still dull. I'm presuming that the bulbs are in the wrong way but I've tried turning them but they seem to only go in one angle and no retaining clip. Two main questions: 1/ Can the wiring socket fit onto the wrong spades on the bulbs? 2/ Is the profile of the bulb important, ie: a shorter, smaller bulb not protruding into the lens enough? BTW: Getting access via the wheel arch (wheel still on).

Eternally grateful for any ideas because its doing my head in.

Cheers. Mick.

[VroomVroomClonk]

You say "no retaining clip", so that is a problem. Each bulb is supposed to have a sprung wire clip that hinges over the back of the bulb and clips into place to hold the bulb tightly into the reflector.