Thanks guys!
I am going to take your advice and ask them to change the battery, like you said, I'm due, as the battery is 5 years old.

I have always taken the car to La Brea Chrysler, in Los Angeles because it is close to my home, and they did some warranty work on it before and all came out ok. But, I don't have a lot of confidence in them because of an incident with my brakes last year. They told me that I needed new rotors$$$$, and when I told them I wanted to take it to another mechanic first and get a second opinion, suddenly they were able to "save" the old ones. Go figure. I am looking for a good mechanic, and after reading the posts here for 2 days, I see that many are using MB mechanics. There are lots of those around where I live. Any suggestions as to what a MB mechanic would need to service a XF?