Below are excerpts from the MOT tester document.
Information:
Vehicles equipped with High Intensity Discharge (HID) or LED dipped beam headlamps may be fitted with headlamp washers and a suspension or headlamp self levelling system.
Where such systems are fitted, they must work; however, it is accepted that it may not be possible to readily determine the functioning of self levelling systems. In such cases, the benefit of the doubt must be given.
Method of Inspection
Where HID or LED dipped beam headlamps are fitted, switch on the headlamps and check the operation of any headlamp levelling and cleaning devices fitted
Reason for rejection:
A headlamp levelling or cleaning device inoperative or otherwise obviously defective.
So, washing/levelling MAY be fitted, and if so they must work. So from an MOT perspective alone HIDs without these will not fail as long as general alignment and pattern etc. is correct.
However, a car with hids driven in Europe must be E-certified, and to do this it MUST have levelling/washing systems. So from a DOT legal standpoint aftermarket hids with no levelling/washing are illegal.
But, like any law, it needs someone to enforce it. If you have an aftermarket system that is close to the look of an oem then you would need the police to a) notice this and b) be bothered to do something about it. They would also have to prove that your install was dangerous. These days they dont even care about incorrectly-spaced numberplates.
I am NOT advocating breaking the law in any way, but I don't see a properly installed aftermarket OEM-like kit as being a bad thing.
I do see badly-installed hid kits, especially into none-projector lenses, that are dazzling and yep, I want them off the roads.