I agree! Mercedes customer service is sinking to new lows. They have tried to fix the sunroof twice by pasting felt strips in critical areas to eliminate the squeaks but, as you would expect, these felt strips eventually come loose during sunroof operation and fall off. Mercedes needs to get real and replace this sunroof catridge with one that has durability.
Talking with Hyundai service writers, they indicate that although Hyundai ahd initial quality problems the dealers have very few warranty repairs anymore. I know of one Hyundai owner who now has 147,000 miles on his car and although it looks poor cosmetically it is still running and driving well.
Personally, I think it will be a long time before Mercedes lives down the reliability problems it is experiencing on vehicles produced since the introduction the the ML in 1998.