Not happy with the H7 dipped headlamps on my 2004 A Class, I decided an
upgrade was in order. Whilst expensive, the only effective way is to
use HID conversions. They use a lot less power than standard ones, and
are up to twice as bright. The colour temperature is also easier on the
eye and shows up road signs/markings rather better.

Choosing them is the hardest part! The facts are, that the closer you
are to a colour temperature of 4500K the more pure white the light is.
Most original HIDs run at 4100K to 4500K. Mine are 6000K and are
slightly "bluer" than this. Some people go for 8000K which is a very
blue colour which looks better from the outside of the car, but starts
to drop off considerably in benefit to the driver.

I bought my units from www.vagparts.com. They come with a laughably
translated & useless set of instructions, but also a sensible mini
guide sheet which is thoughtfully included by the seller. Middle of the
road quality & price.

TIP. When removing the headlamps, you want them back in exactly the same
place (beam alignment etc). Before removal, I closed my garage door and
marked the beam pattern on the inside of the door with masking tape.
When you refit the lamps, make sure the beam pattern still hits those
same marks. Or get them checked at an MOT centre.

1. I have read about people who fit these things in a hour. Goodness
knows where they install the electronic control units (cable ties?).
These units have to be securely mounted away from heat and moisture.
Yes, have a look under the bonnet! Not exactly spoilt for choice. There
is a really handy space beneath each headlamp, but this entails
removing the front bumper and both headlamps first. So the job is really
a full day job to do it well.

The first picture shows the bumper off the car, and the electronic units
bolted to the front crossmember and facing the engine. Due to the
pipework on the driver's side, I had to mount this one at a slight angle
& move one of the horns along a bit. Still, nice and secure and out of
the heat and water though.

2. The wiring is very easy as per instructions, but requires that a 25mm
hole is drilled through the back of each dipped beam bulb cover. No
escaping the need to buy a 25mm hole saw at this point. Picture two
shows the drilled cover with the new wiring & grommet in place.

3. Warning...The electronic units produce 35000 Volts and can give an
electric shock you won't forget in a hurry, so test only with everyone
clear of the wiring. Everything worked for me, so it was a case of
refitting the bumper and making sure there were no "spare" screws left.

The last picture shows the lamps in daylight. Very pleasing. At night
they have transformed the car. Okay, they aren't going to "pay for
themselves" but the car is better for having them.

Thanks to Graeme (Argos) for the pictures and article

If any members wish to go ahead with a headlight conversion please try the link, as you will be supporting the club in the process.