Our '03 L sedan has a history of interesting electrical issues, most (like the DRLs not working) were solved by replacing a failing alternator and/or diode pack.
We bought the car with low miles (perhaps 23K) in 2008. The alternator was new at the time and we've gone through at least one plus an extra diode pack.
Presently, the backup lights are very dim and go out completely when the brakes are applied. In addition, the lights on the license plate don't work (I believe my son checked the bulbs and they were fine).
Any thoughts? If more info is required, please let me know. I don't drive the car much as my son uses it at college.