Rear anti-roll bars!
 

Im contemplating fitting a thicker rear anti roll bar to my ST, ive been told change the rear one only on FWD. Currently as standard its 21mm, but i know of one thats 22.5mm or would a 24mm one ive found be better?

Try them and find out..

The 22.5 won't make much difference. At least Whiteline does Focus uprated ARBs for the rear. At that point it's worth thinking of replacing the rubber bushed up-links with something proper.

Well ive found some 24mm front and rear bars, thatll be a 2.5mm diff on the front and 3mm on the back so should make the rear do a little more work.

When speaking to the trader he said with the bilsteins ive got as they are not coilover these will give me the body roll stiffness of coilovers but not ride. Is this true or utter bollocks.