Ok, I am the new owner of a 2003 E320 Wagon...The car has 123K miles on it and 2 owners...
When I start it I notice I get a message that says "Service B 38000 Overdue"...The second owner acquired the car exactly 38K miles back so I am assuming (hoping) the reason this message is appearing is because he didn't use a ME/BE shop and no one ever cleared the code.
I was going to get an oil change tomorrow and have the brakes inspected (Midas?)
Please give me some advice on what else I should do....
Hopefully that doesn't mean that the oil hasn't been changed in 48K miles! You don't need to go to the dealer to reset the FSS message. The procedure is in the owner's manual. But get the oil changed first thing. I would take it to the dealer. They will use the proper 0W40 synthetic oil and fleece filter. Don't use anything else. Dealers often have oil change specials to get you in the door. Sometimes they call it "basic service". But it usually includes an inspection of other components like brakes, suspension, driveline, etc. I would also have them change the coolant and brake fluid.
Again, I use the dealer for these types of service as I don't really trust indie shops. When I first got my car a neighbor recommended an indie shop so I went there for my first service and they put 20w50 dino oil in the car! (I didn't know any better until I joined this forum.)
Next, I would get the transmission serviced - at least a pan drop and filter change. Don't have it pressure flushed!!! And, while you're at it change the 13 pin connector from the trans to the wiring harness. (Only use genuine MB/Mopar) These leak and trans fluid wicks up into the trans module, causing shifting problems.
Spark plugs should be high on your list.
Also, replace the idler pulley on the front of the engine. They are failure prone and it's a cheap and easy job. While you're there inspect the serpentine belt and replace if needed.
I wouldn't worry too much about the brakes. There are wear sensors that will let you know when the pads are gone and, if you don't get vibration when you step on the pedal, the rotors are probably still ok.
I know that sounds like a lot but, with some prudent preventative maintenance, you can enjoy that car for the next ten years.
Good luck and welcome to the forum.