I'm completely baffled now. If the beam on the C5 with xenon headlamps is truly symmetrical and not biased to the left or the right, then what is the reason why the French authorities have cause to complain, given that EU Regulations permit the option of a symmetric beam or an asymmetric one with a 15° bias towards the nearside. It is true that countries do have the freedom to restrict certain EU requirements if local conditions are so specific that they call for such measures, but there cannot be anything so specific about French traffic conditions that would make an asymmetric beam in their country mandatory. Besides, it would mean that cars coming into France from another country where one also drives on the right, would fail, too. Without a detailed explanation from the French authorities I can only assume that either, 1.) they are apparently not aware of the information that Citroen have supplied concerning UK market vehicles with xenon headlights or 2.) the information from Citroen has been checked by measuring beam distribution and found to be incorrect.
I was always under the impression that, due to local conditions, the UK does not permit a symmetric beam, but I stand to be corrected. The only reference that I can find in the UK regulations is, quote, "Every dipped-beam headlamp fitted to a vehicle first used on or after 1st April 1986 in accordance with this part of this Schedule shall be designed for a vehicle which is intended to be driven on the left-hand side of the road". Whether this amounts to a mandatory requirement for an asymmetric beam, I don't know.