Hi all 

new to focus ownership and so far enjoying it....my question regards the rear upper control arms. I will shortly be changing the trailing arm bushes which shouldn't be a problem having changed many before, and at the same time I want to change the upper control arms, not the one with the spring cups in but the banana one and the short one, I've watched a few videos  and it seems that the bolts will probably be seized into the metal inner of the bush again not to much of a problem as a reciprocating blade will cut through the bolts as in the videos but my main concern is the top control arm bush nearest the middle of the car, I cannot see from the video but I think this bolt has a captive nut due to restricted access so if I cut through the bolt this will leave a section of it still in the captive nut flush with the mount, has anybody come across this or have a solution to get the bit that's left out?

I removed these very same bolts from my 2016 mk3 not long ago and had no problem doing it. Yes there is a captive nut as you say, cutting the bolt imho is not a good idea, you will have very little access too what remains unless you drop the subframe if you do cut it.