I too have had nothing but problems with my Saturn L300. Like someone else on this site, I have had to replace not one, but 2 mass air flow sensors, a starter sensor, and an ignition tumbler and cylinder housing.
I am not happy with my purchase and will never buy another Saturn again.
Yes I myself bought a used Saturn L300 back in 9/06- I already had to replace a mass air flow center myself and as I type my car is at the dealership getting a replacement of my ignition housing and cylinder. If I knew that this happened to this certain type of car- I would have never purchased one.