First thanks for the great site, I have already got a lot from it.
I just picked up my 2005 Focus CMax 2.0 TDCi yesterday, the dealer put 12 months MOT on it so I was a bit surprised to find that the offside lights were shining about 3 feet in front of the car once it got dark - something I hadn't thought to check before setting out as the sun was still shining at the start of the journey. The headlight leveller in the car didn't make any difference either. On checking today the adjuster (yellow allen bolts on top of the headlight unit) didn't make any difference either. I took the unit out (thanks for the video elsewhere on this site) and it became apparent that the adjuster had become disconnected. The lights hang from 3 ball and socket joints within the unit, one adjusts up and down, one side to side and the other has the leveller on it. I managed to pop the joint back in by slacking off the side to side adjuster and screwing in the up/down adjuster as far as it would go, applying a little petroleum jelly and using a bit of force.
Its a bit fiddly but better than paying for a new unit. Anyway I did a bit of thinking about how it could have been broken - I guessed that the car failed the MOT on a bulb and when the bulb was replaced the joint popped out. I know they shouldn't have but my guess is that the MOT test got passed because the bulb was working and they didn't re-check the alignment . I called the dealer and he confirmed that an offside bulb was replaced as part of the MOT. So I guess the lesson is to be careful when replacing headlight bulbs.