Yea I definitely agree with Sick, check the frame, and the torque boxes also. Go under the car and check out the condition of these two important things. If you got a frame that is just flaking and falling apart and looks like Kellogg's corn flakes cereal, then you need to get all that replaced, if not the whole frame... and then after that repair, bring it to a body shop and put on a jig to pull the unibody back into factory alignment.
But if the frame looks good with just a few rust holes, have it patched up and check your suspension like Andrew said.