Ryan,
I'd take a close look at your trackrod bushings. The track rod runs from the lower control arm diagonally back to the subframe. The bushing at the subframe can look ok from the outside but be completely shot. With your car on the ground try kicking the tire forward and back in the wheel well. Have someone else drive slowly forward and back applying the brakes hard and look for movement or listen for the characteristic pop. When these are worn any unevenness in the tire or rotor can be magnified in to one hell of a shake.

Bob D.
Parrish, Fl
3 SDs
1 SDL
4 Mogshttp://photos.yahoo.com/h2odiesel