Warranty repair?
 

A buddy of mine took his mini to the dealership for new tires and alignment. When he went to pick up the car, the service guy told him the alignment could not be done due to worn ball joints, front lower control arm bushings, and front strut support assembly guide support.

The strange thing is the ball joint was covered under warranty, but the control arm bushing and guide support were not. They simply said that it's the drivers fault, likely due to hittingpotholes. I looked up these parts online and it seems they are a common point of failure:
http://new.minimania.com/web/AddedFr.../InvDetail.cfm

Should this repair be covered under warranty, just as the ball joints are? The car is a 2005 cooper convertible with about 40K miles.

By the way, the dealer wanted $1900 for replace these parts on both sides.
Thanks in advance.

For anyone replacing their control arm bushings and ball joints: Pelican Technical Article: MINI Cooper - Control Arm Bushing and Ball Joint Replacement

-Jorge