My car sways left and right on high speed and on overtaking.Also it sways when i kick down and during changing gears.Its very annoying an.Yesterday i went to the aligment specialist to chek it.He parked the car on the hole and tried to move forward and brake,He determined that the back of the car is swaying.He told me that the problem is from the brackets(bushes) that hold the back suspenion(hold the axle,differential) with the body.There are four and their cost is nearly 150$.Also it tooks too much work to install them.Is it safe to drive like this?