After market HIDs are not illegal as long as they pass the beam alignment test.
Sorry, but that is absolute bollox.
Washers are also not a legal requirement when fitted after it has left the factory. The washers are only required on cars that are built in factories (so standard xenons that come with the car)
Again, bollox. Headlamp washers, and more importantly, automatic dynamic levelers are absolutely and categorically legally required. It is both a UK and EU legal requirement. Retro-fitting HIDs without the full OEM gubbins will invalidate the "Type Approval" for the car. This will then invalidate your insurance (even if you do actually declare it as a mod), and will also lead to potential criminal prosecution for a breach under the "Construction and Use Regulations", and a breach of CUR is also a breach under the Road Traffic Act.
You cant fail an MOT for something you do not have to test, a good example is the spare tyre in some cars; if its bold just take it out before the test, if they cant check its bold they cant fail you!
A spare tyre is NOT a legal requirement - otherwise how come all these cars with "tyre mobility systems" (a bottle of slime and a mini compressor, instead of any kind of "spare wheel") can pass an MoT!
Correctly functioning headlamps which comply with the manufacturers Type Approval ARE a legal requirement, and a testable item.
I have aftermarket HIDs and it flew through the MOT last week. Its now passed in a Honda garage and my local garage.
Then you have just admitted to not only an illegal car, but also a dodgy MoT. 
Firstly, telling me im admitting to something illegal when an 80+ thread on street racing is only a few posts up is abit silly. My HIDs wont kill anyone, spinning out at 100mph while racing will.
Anyway, yes you are correct. My information was from a few threads which i searched for and didnt look at properly (they were dated 2007) so apologies for the false information, at the time this was theoretically correct due to loopholes (although i agree, illegal and so yes incorrect)
There is alot of loopholes currently surrounding aftermarket HIDs and even factory fit HIDs, as you say headlamp washers are a legal requirement; how is it then that the integra DC5 is legally imported to the country and they come with HIDs as standard with no headlamp washers (as does the JDM ep3) My lights are technically legal as they pass the beam scatter test, unfortunatly most MOT testers (also police) dont realise the actual legal requirement involving HIDs. Also without a complete list of cars that roll out the factory with xenons fitted with all the correct legal parts its impossible to do anything, how would a police officer or mot tester tell someone in a DC5 they cant drive their car with HIDs when it came as standard?
The fact is unless they stop places like hids4u and other similar sites/traders selling aftermarket HIDs and release every car that has been made with HIDs/xenons as standard (inc plate/vin number) its will be very hard to stop them being fitted to cars.
All i know is my car is much safer as i can see much better at night, and i have never had anyone flash me in the last year i have had them.