So I just bought my 3rd Mercedes and this one is a 2005 E320 wagon with 66k miles. Right away I noticed it has some electrical problems and car fax shows a new battery every 2 years. My question is does any one know the root cause of these issues? In this year did they use bad sensors, or was it poor wire (saw some previous years used biodegradable wiring), or just poor design? Like to see if I can get ahead of the problems since the engine and trans are awesome! Thanks for your thoughts!