How do I tell if my shocks and CABs need replacing?

Car is a 2003 E46 330i.

I have about 54K miles on it, and plan to keep it for a few more years.

My question is: Is there any objective way to tell if the shocks need to be replaced, other than age/mileage?

On my 1963 Dodge Dart ( I'm not that old, I bought it used when I went through college in 1978 ) I would bounce the corners up and down several times; if there was any wear, they would bounce on their own more than once, indicating a need to replace.

Is there a similar test for my car?

Also, for the front Control Arm Bushings, what. if any, is the objective test for these items to need replacement? I've been under the car and inspected them, but aside from normal road dirt accumulated after five years can't really see any problems with them.

Would both of these components simply be replaced as a matter of course at a certain time or mileage interval?

If so, what would that be?

Thanks in advance...

It's my understanding that control arms are just a "replace as you need them" type of item and the same with shocks/struts. These usually fail at different times so I don't think there's a set mileage interval to replace them. BUT, if I had the money, I'd replace them every 90k, but since I'm a broke mothaplunka, I'm still holding off on replacing my rear shocks even though they're probably shot (squeak over bumps).

For the CAB, inspect for cracks in the bushing while levering the Control Arm an several directions.

A 5 year old 330i ZHP with only 54k miles. I would be shocked (no pun intended) if you needed either. For sure the shocks are still viable if they don't have obvious fluid leaks and/or the car is not doing anything weird turning into or accelerating out of corners. The Control Arm bushings are harder to diagnose but if the steering wheel doesn't kick back slightly under initial medium braking from over 40 MPH and they look fine, you need to worry about something else.

Let's see a 5 year old E46... A new battery, Inspection II is coming up, It will need brake rotors soon, always tires, how about some Dinan upgrades?

Enjoy,

Thanks for the tip, appreciate it.

Already did the brakes (front and back, Zimmerman rotors and Axxis/PBR pads), battery (last year), and a set of tires (Pirelli Pzero Nero's on sale at tirerack for - get this - $530 for the set - I think they were closing them out. )

I had my used 325 inspected and I noticed oil leaking from the rear shocks. The car drove fine, but the dealer replaced them under warranty.