My 97 e420 has 62kmi.
I had it to the dealer twice for slack in the steering. They replaced both front control arm bushings the first time - it was only 50% better.
Brought it back to another service team. They had to redo the bushings (said they were incorrectly installed) and replaced one of the ball joints.
The car is still not perfect. Especially on rough surfaces and bumps the car wants to sort of do its own thing, forcing the steering.
Any thoughts what else it could be. It is 80% but not perfect - the dealer got on my nerves and I will be going to an independent (another reason to buy 3rd party extended warranties).

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2008 S550
2010 GLK350
1997 E420 (retired)
2005 CLK500 (retired)