hello mate
with my exsperience fk's lower the most out of ANY kit with the adjusters in as they must have the shortest rear springs i was in the same situation as you and wasnt happy with the rear height (still to high imo so i removed the adjuster block that goes under the rear springs (where you adjust them from) this lowered it easily 30mm more
but be careful as the exhast is litrally sandwitched between the axle and the boot floor specially if your like me and have a milltek.
anywayshere a picof my car yesterday just before i raised it up again!
had no rubbing AT ALL on the rear and the front was nearly at the bottom setting and rubbed when going down bumpy country roads looks nice but UNPRACTICLE so decided to drop it more than with adjusters in but not so low i cant drive it
so raised it to this nice ride height (better handling aswell)
now there is no gap between tyre and arch but not hiding the tyre