Read up on your local laws regarding salvage/rebuilt titles. Typically a "salvage" title cannot be registered and driven on the road. Once the car has been rebuilt and gone through an inspection process, it can be issued a "rebuilt" title. Rebuilt titled vehicles can typically only carry liability insurance.

An interesting loophole is registering in a different state. My 350SD was "totaled" in 2006 in a very minor front end collision that damaged the hood, top radiator brace, and AC condenser. Car was registered as "rebuilt" in West Virginia and carries the certificate that it passed. When the car was registered in Texas, it was issued a clean and unrestricted title with a footnote that it was previously "rebuilt" in WV.

The quality of the rebuild job is directly related to the quality of work coming from the shop who performed it. In the case of my 350SD, the only clue that anything has been done to the front end is an emissions sticker on the radiator brace from a 300SE.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]