I have the same problem and I showed the symptom to the service adviser. We agreed that upon the next service interval, he will order for the entire assembly to be replaced including the mirror, motor and the body wrap with a paint job.I have a 2013 Tech Package 3.8 Genesis. My driver side folding mirror folds in about 1/3 slower than the passenger side... sounds small but looks pretty terrible.
I took to dealership and the service advisor said he can't really do anything about it. If he put a new motor in, would do the same thing. This strikes me as BS unless the quality control is so bad they can't have the same motors operating on the same voltage/amperage/whatever, with the same gearing.
Has anybody had this issue, and/or heard similar in the past?