[300zxtt]

Yes this correct.
Just had the rear arms done on my 2002 4200 at 24000 miles. This is an age thing rather than mileage, the bushes perish. As you say you can't buy just the bushes, just the whole expensive arms.

The rear wheel alignment has to be reset with shims which is a big /specialist job (can take several hours)

I think all 4200s will need this doing sooner or later as they get older.

 

[300zxtt]

I had the car up on the lift last night and saw those rubber bushings.. I am sure it was easier and cheaper to manufacture the arms this way but way more expensive for the customer to replace.... My bushings look good at this time but I can see that in a year or two, I will probably be doing the same thing, getting them replaced..... So anyone here know the price??

UK price is around £1000 fitted.
You will get a light knocking noise on rough/bumpy roads when they are on the way out.