Having had fog two days in a row (-4 and freezing fog this morning) I decided to fit my new whiter xenon fog light bulbs, they look like this:
Very easy to fit. I didn't raise the car. By lying on my back I undid the three (philips head) plastic rivets, and pulled the liner down. It stays attached but is very flexible. Reaching up you can feel the connector. Pressing it on both sides releases the plug. Looking in the lens of the light you can easily see which way to turn the bulb to extract. Insert and turn the new bulb. Re-attach the plug with two clicks indicating the plug is in place properly. Replace the liner and fasteners.
Result. Pretty good, not as white as the supelux LED sidelights, but a good couple of shades whiter than the stock foglights, and a little brighter to my eyes.
Also note there is a knob below the light fitting that looks like it allows the horizontal angle of the foglight to be adjusted.
