I find it hard to beleive that it has brake shudder as we have done two 300km tests on our turbo at eastern creek and been through two sets of pads and still have not machined the discs and there is no shudder at all. But i can say that it may be possible if :
wheel nuts have been over tightened
going through water with hot discs
washing the car after a long drive
small grit between hub,disc and wheel surfaces.
either way get your dealer to check it out but im sure it wont be covered by warrantee.
The BA has different brakes to the AU, they may look the same as the series III AU but they are totally different in design as the discs and Pads are not the same.
OMEGA AUTOMOTIVE CENTRE1/ 191 Fairfield Rd Guildford West
NSW 2161 02 9892-2499