Do your homework on used car purchases. Check popular ad magazines and online listings for the market value. You can also get a history of a vehicle for $25 or so through Carfax and other services if you have the VIN. Some cars have VINs in different areas such as trunk, dash, doors. If they don't match then something has been replaced. Ask questions and see if the seller looks up to the left to make something up.
On that car I would check the underbody for rust including the engine cradle and sub-frame mounts and rocker panels. They look good from a standing position but get down and look under for a real evaluation. Pull the trunk carpet back too to look at the wheel wells and rear quarter panels. Who knows, you might even find glass fragments from a rear ender.
Most of all read the postings on Automotive Forums for frequent topics.
Good luck.