The OM states that they operate on a high voltage but the implications of this are not made clear. Now, looking at Xenons generally, it seems that they are meant to have an extremely long life. However, when/if they fail the unit price of a genuine replacement might be £70 - £100 or so (excluding the ballast). This is an internet estimate and not a Vauxhall one and in 2005 someone was quoted over £400 to replace one on a 'German car', which involved removing the bumper and front bits of the vehicle to access the unit. Apparently some bulbs have a built-in motor for adjustment. How much of all this applies to an Antara I have no idea, but clearly it is not a matter of buying a bulb for less than a tenner and changing it yourself in 15 minutes. I too have Xenons and let us hope they do indeed last the life of the vehicle. Should a replacement ever be needed I should be wary of buying an eBay equivalent (probably from China under a disguised address). I have bought a few minor electrical bits this way and they really are not up to the mark, although they are less expensive than the bona fide item.
Perhaps one of the forum members with experience can throw some light on this subject?
2015 2.2 CDTi SENav 163ps manual 4x4 in Carbon Flash with 19\" alloy spare towing a Bailey Unicorn III Madrid @ 1500kg.