I have to agree the oil change places are sometimes pretty bad. They always are trying to sell services that are not needed. I find that they are good for a quick oil change without having to set an appointment with the mechanic.

If you go in and are able to tell them a lot of information about your car they tend to leave you alone. When they ask "what kind of engine do you have" (they are looking for the 6cyl 4cyl 8cyl info for their computer) the best answer is "This car has the OM617 5 cylender turbodiesel". When they have a customer that know's their car in and out their ability to lie and be deceptive is very much compromised. Most of them won't go through the trouble with me but end up dinging me for the extra oil that my car takes. If you look at the fine print "on the wall" only a certain amount of oil is included for free. I honestly don't mind paying extra for the oil and most of the time bring my own. The ones you need to avoid are the ones that blanket charge extra for BMW and Mercedes. If you see that on the wall run back into the bay quickly and tell them to stop before they start work. There is absolutely no difference between a Chevy or Mercedes when it comes to changing the oil.

These guys are trained to smell blood in the water so don't cave into their lies. If they detect any lack of knowledge on your end they go in for the kill and many times suggest your car barely made it in and do a hard sell claiming you won't make it out of the service bay let alone down the street.

Whats even worse than the oil change places are the brake places. They use all sorts of scare tactics and even quote "laws" about caliper thickness that don't exist. Many of them will pull apart your brakes and then try to sell you extra services and "refuse" to put your car back together unsafely to sucker you into repairs. Of course most self respecting Mercedes Owners should avoid "tune up clinics" and any Brake places like the plague. They know nothing of the special features of the engine and braking systems and do substandard work.