wen I got hit in the rear it damaged the drivers side quarter, the boot lid, the reo, the bar, the mounts, the boot (Floorpan?) and a whole bunch of otherbits and peices like the lights, etc, etc.
But when I got hit it was a fair whack, so it's all possible, go get a few quotes and have them assess the vehicle, if you get a few quotes you can quickly compare them and see if anything looks like it could be bullshit added to make money or whatnot, but you have to be damn sure, not everyone out there is a prick.
Just in the case of who is at fault, not ALL rear enders are the rear enders fault, if you fail to give way and get rear ended, it's your own fault (Just an example) if you do a right hand turn across an intersection while a red arrow for right hand turns is facing you it's your own fault as well.
My advice is go get some quotes and go from there, you should be able to find a company that repairs bars and they do a good job too (Pretty sure they garentuee the repair)
If you don't put an insurance claim in the second it occurs it isn't a big deal, so take some time and sort out some other options.