Yoru best bet is to look at the car really well...
My last truck was in an accident, sold it after $8k was put into body work and pulling the frame and it carfaxed clean, my current msutang was in a decent accident (airbags had gone off, hood cruched, front bumper replaced, damage near the brake vent on the pass side, smashed rear bumper cover) and it too carfaxed clean, but I saw it before the guy fixed it up a bit...
Take a good hard look around all of the places you can align body panels (bolts for front fenders, how wiring is run, gaps between body panes, cracks in grill or other out of the way pieces, etc).