Sedan, or saloon is a type of passenger cars which have a three-box configuration and separated compartments for engine, passenger and cargo.Usually, a sedan has the following definition: have a B-pillar that supports the roof, two rows of seats and a closed mental roof. In different regions, people use various classifications to define a sedan.For example, companies use the grading standard from General Motors Company to grading sedans such as LowMed, Intern and Large/Lux. For Europe, they graded the sedan from A to D class. Basically, most of the normal family would tend to buy a sedan not just because the sedan is economical and practical but also easy to maintain. Commonly to say, a sedan would have 15 years life for the sedan under 9-seats and 10 years for above 9-seats. Or if we pick the view of mileage, sedan usually can be used for 500,000 kilometers.