Review: Why does an insurance company stick the title "salvage" on a car? Because the cost of repair exceeds the value of the vehicle. So imagine the damage that would have to take place in order to make a new $50,000 car not worth repairing. That's a serious crash, and it's likely you don't want a car that's been hit that hard.
Now imagine an older car. It might only take a fender bender to total a car with a Kelley Blue Book (KBB) value of $5,000. These reliable older cars are generally the best salvage buys.
This should help you evaluate a dealer's description of damage compared to the price of a car. If you come across a salvage dealer claiming minimal damage on a new car, your spidey senses should start tingling. Just like anywhere, a deal that seems too good to be true probably is.