Is it flood damaged? If it's just been totaled and repaired with a salvage title it's a different thing altogether. I would be looking at panel alignment inside (air bags) and out, abmormal squeaks and sounds, rust where it shouldn't be, immediately change all fluids even the sealed fluids like the transmission. I would also see about removing the underside protective layer and check out if there's anything hiding up in there such as salt or rust. It hides a lot of that. If they let you, take it on a drive that gets it up to temp and run it through it's paces too. Use a code scanner and scan it as well for any codes it may be throwing but not showing an error message.