yes the dreaded arb links, seems like they are a real inherent problem with focuses.

i replaced my front links with some of ebay(only a tenner)and it is a pleasure to drive again, its surprising how quickly you can fall out of love with a car!! now i am getting a knock in the rear, plus there is a slight creak when i get out as well(when the weights been taken off). if they are as cheap then its worth getting them changed, because they WILL go eventually, but the other bushes are a bit more expensive. if it is the bigger ones, i would avoid using poly bushes, these might give a slightly better handling, but for day to day driving they are murder. i got some for a audi 80 coupe i had and along with lower suspension and bigger wheels with lower profile tyres it rattled all my fillings loose!!!!?

any way, if the arb links need replacing dont bother trying to unbolt them, a quick blast with the grinder will have them off in seconds. just make sure you have a trolley jack under the anti roll bar in case of any load that it might be under.