Unless you have the money to spend and don't especially care what it costs, the best way to own a Mercedes-Benz (my opinion, of course) is to get a used one in the best condition you can afford, after having it checked out by a pro, and do not depend on it for daily transportation, but only as a nice toy that you use occasionally. That way, you can keep it in near-perfect condition at relatively low cost, and it won't cost you a fortune, and you will enjoy it a lot more. Plus, if it breaks, you can let it sit in the garage in all its pristine but immobile glory, until you can get it fixed. Friends would come over and admire my 420SEL in the garage, never knowing that it would not run! It does now, very well, and I put about 1500 miles a year on it, at almost no cost. If you want to hate a Mercedes-Benz, go buy one, especially an S-Klasse, at a bargain price and try to use it for daily transportation. Daddy Warbucks can drive it happily because he can write the check when it quits and doesn't worry about what it costs too much.
Second-best way: buy a new or certified pre-owned car from a dealer; a car with a warranty; when the warranty expires, goodby.