One other free way of improving the light output is by cleaning the actual fresnel lens in the projector.
They go cloudy with grime over time, and it's an easy job without removing the headlight. This applies to both halogen and xenon lights, pre and post facelift.
Simply remove the back cover and dipped beam bulb, then remove the 4 x 7mm nyloc nuts that hold the projector assembly in place. This then comes out easily.
You then simply clean both sides of the lens with a soft cloth, DON'T touch the reflector!
The difference is remarkable..
Before and after;
The other option is a hid kit, yes I know the arguments, but as the halogen and xenon share the same projector, I don't see the problem. Don't bother with a 35w kit, go for a 55w 5000k kit WITH metal based bulbs. The plastic ones don't fit properly.
Mike