I find this ruling very ambiguous and un-clear. They talk about the HID in general terms yet they're forgetting to clearly mention the type of HID bulbs being used. The issues they raise in their statement regarding glare and un-even light pattern was indeed present with the older type HID kits which use a dual core bulb technology, however this was long overcome with the introduction of a single bulb technology which uses the same bulb for Hi and Lo beam and the cut-off line is VERY precise with no glare whatsoever.Hi Rob, All interested parties.
See this from the DfT website
Department for Transport - Aftermarket HID (Xenon) headlamps