I likely felt like you did; my new car needed work right away. Actually, both of my Mercedes did. The difference was that I knew a great deal about the 2nd one and nothing about the first. Since owning both, I have realized what ymsin said, you replace a part and forget it. Also, these cars were extremely expensive when new, well beyond my means, and yet, with some work I can have the same quality ride on my budget. This is currently truer with my 300E as it now feels like a new car. My 560SEL still has a steering problem to work out.
Good luck, welcome to the club. Mercedesshop that is. Here you will learn all you need about your car.

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VR
1967 250SL