i can add to this... my good friend bought a 2005 gmc sierra that had been in a front end collision and he and his dad repaired it. they did an excellent job and the truck "looked" like new, but as a result of this crash, he has had endless problems with the air bags since, problems with the drivetrain, and any other imaginable problem down to failed seatbelts and broken seat brackets. thing is, when a car is in a crash like that, it'll never be back to how it was before.
I also had a similiar problem with my Olds Alero. It wasn't totalled but the previous owner had a significant crash where the entire right rear had to be re-done with new sheet metal. now, i am experiencing bad rusting and paint peel from poor body shop work. also, I had supension problems because the sway bar was broken and never repaired.
'00 Oldsmobile Alero GL
'92 Buick LeSabre Custom
'95 Pontiac Bonneville SSEi (sold)