hi, as for your problem with the rust under mirror bases.
i had the same problem about 18 months ago.
this was carried out under warranty, but i had to contribute towards it.
i had to fight hard with ford customer care as i was not the first owner.
i was second owner of one year old car with 10.000 miles on the clock.
it had done 22.-25.000 miles when complaint.
ford tried to pay the minimum until i told them this was my third focus and i could not believe that a car of 18 months had rust.
so if your car is older you will have to fight harder(but stick to your guns)
it works.
ford then paid 95% towards the cost

let me know how you get on.

borgie.