If you've heard a rattling noise for "MONTHS", wouldn't that be a sign for you to atleast visually look at it yourself or take it to the dealer. I know taking it to the dealer is not always an "easy" option as it seems, but if my car - even if it was a $500 beater - started making a noise that was not normal, id visually look - you could prob see the leaking shock. --- But if your car is under warranty, then why wouldn't you have taken it to dealership right when it started to make that noise?
As far as the bushings, I highly doubt they will replace it under warranty now.
I don't understand how you have "no choice" but to keep driving the car like that. Are you dumb or just stupid? Why the hell would you make things worse? Do you raelly think BMW will replace your other parts when you tell them you've been driving around with a worn out bushing (and known about it) for months? Many people will point to the fact that if you do not have the funds to maintain your car, you should have not bought it in the first place as these are high maintenance cars - however, if it is going to "make things worse".. do you expect it not to cost EVEN more after you proceed to drive on broken suspenion parts? god forbid you hit a pothole or something.
Take a loan out; borrow some money from grandma; get a second job - but DO NOT keep driving your car. Each dealership is different - but good luck getting your bushings covered under warranty; because I don't see that happening.
I feel bad for your car.
2008 CPO 328i Jet Black, Premium, Sport, Manual, Xenon.