check the ball joints every year or so, put the car up on a jackstand such that the weight of the car is on the lower arm, then use a 2x4 to move the wheel up and down, if you can feel or see movement, IMMEDIATELY replace the joint.

similarly if the joint squeaks when turning it is dead and is on borrowed time. I also make a habit of turning the wheel and checking the boot for tears, if the boot is torn then the joint is bad, if the joint is cast into the arm (sportline etc) then get the boot kit and replace them immediately. You might save some time.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)