I'm returning my 2018 X1 and taking delivery of an X3 next month. Sadly the bars aren't compatible.
Part number 82712350126. They're currently on my car and look/work great. Available to pick up after July 12th. Can be shipped anywhere in continental US (buyer pays shipping)
As far as I understand they fit 2017-2021 X1 but feel free to double check me!
EDIT: Uploaded some pics in my next post