If it was dead center before and now it's off center, they didn't do a good job. But if it was off centered, you can always request the tech to center the steering wheel during an alignment. Most of the time, they don't pay much attention and just perform alignment and road test. My e39 and the ML both suffered this off center (slightly) phenomena and both were fixed after an alignment. But I have to mention it to the tech so that they know.

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98 ML320 (gone but not forgotten)