My dealer says the ONLY difference is that "B" service replaces the cabin filter. My car was due for "B" service. I had them perform "A" service and saved the additional expense. Replacing the cabin filter has nothing to do with protecting the car or maintaining the warranty. It really only needs to be replaced if there is inadequate air flow or if it is losing its ability to block outside odors. The filter OEM price is $34.50 and can be ordered online for $27.60. It is located behind the glove box. It appears that it can be replaced in about 15 minutes (requires removal of about 6 screws)

 

What is the price difference from the dealer for Service A vs. Service B? The $6.90 savings in the filters seems almost not worth the hassle of ordering it and waiting for it.

 

I had service "A" done last week for $129.95. Service "B" price was $229.95. I also had brake fluid replaced for $69.95;

There are lots of posts where others have paid well over $200 for service "A" and well over $400 for service "B". Some paid as much as $549 for service "B".

There are 19 Mercedes dealers in Southern California. A couple of times a year, at least one of them offers servicing at low prices for about 30 days. Most of the other dealers advertise that they will match any local dealer.