xreyuk, the "standard" replacement bulbs are fine. Such as Nightbreaker, Ring, Philips etc. No
problem whatsoever, just a direct replacement.
It's only when you
modify the lighting system by adding the aftermarket HID kit hardware such as a HIDS4U kit, which means adding ballasts that are wired into the cars electrics plus the special HID bulbs etc, that you open yourself up to these new MOT laws.
Also, the standard headlight reflector isnt designed to work with HIDS as far as I understand, which adds to the glare that these kits might give out. That, and not having them re-aligned properly after fitting, which is a
problem too, for other road users.