A note is when I was at the workshop servicing my car, an owner was there to change his suspension for the first time. I was shocked when he told me the mileage of his car - 400,000 km. He replaced his suspension at this mileage. My car is only 80,000 km. I guess I have to drive a bit more get the suspension to show more wear and tear before I replace the whole thing. Perhaps I'll just live with the minor noise of the front suspension. The sound will only come up when driving over speed bumps at moderate speed of say 20 to 30 km/h. If driving at 5 to 10 km/h over these speed bumps, the sound won't be heard when the car is driven really slow.

Depends on whether your absorber can be refurbished itself. For coilovers, I remember paying around RM900 to service the front pair.

Distance does not meant anything much. High mileage due to lots of highway drive probably less abusive compares to a town with bumpy roads 

Front coilover service for RM900. Must be premium car I guess. If service front and back together, the cost would be higher than replacing all the front and rear suspension of my car.

my car got sound when hit humps and diagnosed lower arm

mazda car? if it is, then its normal

No noise from rear absorbers yet so will leave it as it is.

For those who have replaced the absorbers for your car, do you do it all at once for both front and rear, or the front first and rear later on? What are the symptoms that caused you to change the rear suspension? Noise, handling or something else?

Guys, just an update. Replaced the front absorber (L & R) and the noise is all gone.

Chose the original version as was informed that there are many complaints for the Monroe absorbers after they were fitted onto the car. The Monroe absorbers are cheaper than the original absorbers.

The old front absorbers in poor condition:-

Look like the absorbers are not returning (extending).
The nitrogen gas inside leak out, can cause noise.

The fine dust which is brownish in colour, that is from the absorber cover or something. Something has decayed and turned to dust.

According to the boss of the workshop, he said he hasn't seen anything like it before. I wonder if that's true as if the worn absorbers are the worst he's ever come across. Anyway, it's all good now. No sound and quiet, and drives a bit like new. Rear absorbers still holding up well so won't replace it unless there's noise coming out from it.