You may also want to take into account.Ideally you need to weld the rear shock upright's as when you think about it when you go to coilovers you are doing away with the spring underneath the car.So you are putting all the stress on 1 point (where the shock bolts) And also been told that fitting of a rear strut brace is needed.You will also find that you get a bit of vibration through the car where the coilover rubs against body as instead of just a shock going up the hole you now have a shock + spring.Hth