Originally Posted by sig11

Yup the front. First half of the session felt good then I started getting severe vibrations under braking. Rotors looked fine and the car felt ok in the paddock so I pulled the wheels and saw that the front UCA bushings had completely given up. The other side were almost as bad so I chucked 'em.

Maybe I was just lucky... I believe I only had 4-5 track days on them at that point. I'd have to check my notebook.