Perhaps most famous for its polymer body panels, the Saturn SL compact sedan is the most popular model in the lineup. This design choice is responsible for a drastic weight reduction compared to other vehicles in its class, which contributed to very good gas mileage and low manufacturing costs. From the start, Saturn really was a "different kind of car company," making a truly new breed of car. Saturn SL parts are virtually all unique to that vehicle, and are not shared across many other GM lines. This was a big difference between Saturn and other GM brands. Fun fact: early SL models were notoriously easy to steal due to weak internal door and ignition lock components - and in 2003, the 1995 Saturn SL was the most stolen vehicle in the US.