Saturn has taken the L-Series and put it under one name for 2004: the Saturn L300.  The main changes from the L-Series involve engine power and options.  The L300 comes in 6 trims: the L300 1 Sedan and Wagon, L300 2 Sedan and Wagon, and L300 3 Sedan and Wagon.  The L300 1 trims use a 2.2 L, 140 hp I4 engine while the 2's and 3's use a 3.0 L, 182 hp V6 engine.  Saturn has eliminated 5 speed manual transmission and instituted 4 speed automatic in all trims.
The I4 trims will get you 24 mpg in the city, 33 on the highway while the V6 trims get you 20 mpg in the city, 29 mpg on the highway.  Cargo space remains the same as the L-Series, with the wagons giving you 33.5 cubic feet and the sedans giving you 17.5 cubic feet.  Standard safety features include ABS brakes and traction control on all trims.  Saturn has added a twist to the L300 3's by giving you a choice among a dvd system, power sunroof, or a one year subscription to OnStar.  Other standard features include power windows, cd player, and power door locks.
Outside semantics and a slight increase in engine power, not very much separates the L300 from the L-Series.  Drivers like the relatively smooth handling and decent gas mileage.  However, wagon owners would also like to see better materials for the interior and better options.  Sedan owners consistently mention road and engine noise.  Overall, the 2004 Saturn L300 has simply carried its midsize predecessor's torch under a different name.