You're right, the Chrysler dealers are clueless, and the Mercedes dealers may not want to work on them because they say "Chrysler". If you can do your own oil changes (which are very easy in these cars), then you will save big $$$ and make sure the change is done correctly.

This forum is your best resource for troubleshooting and repairs. Almost any issue you will encounter has already happened to someone here, and the "Search" function is very powerful.

If your battery is white and says "Varta" on it, then it is probably still the original. Even without the alarm problems I'd get a 7-year-old battery replaced ASAP. At that age they can die suddenly without any warning leaving you stranded, and the Group 48 size batteries we need may not be in stock at your local parts stores. In fact, I'm picking up a new AGM battery for mine this afternoon.

Good luck!