We have a 2016 X1 18d, On the face of it, it drives well and is comfortable. It has a hitch and effortlessly pulls a bike trailer with a R1200rt...
Have had 2 issues in the last year,
Small spring in the gearbox/gearshift controller which throws an error of Car Not in Park when the gear is clearly in park. This requires the replacement of a 5 Cent spring. Expensive job in garage, but is a great DIY option, with lots of resources online. The centre conole has to come out.
Details at https://f48.bimmerpost.com/forums/showthread.php?t=1598332&page=8 with a full step by step video at https://www.youtube.com/watch?v=NMhjjwtcoyw
Second issues was the Drivers side Heater Blend flap was over extended by actuator to lock it in cold air, which over the winter was a real pain...BMW wanted a new heater, new this and new that and may require a dash out....ouch.
Resolution for me, Actuator failedcalibration in ISTA+ - Lucky it was locked in one position so i just had to remove the actuator and unlock the flap as the actuator over extended the flap. To prevent it happening again, I refer to this thread on the mini f56 forum which shares similiar air controller - https://www.minif56.com/threads/drivers-side-heater-blowing-cold.89268/?post_id=887638&nested_view=1&sortby=oldest#post-887638 - full details...
As an insurance to prevent this happening again, Ibought a 3D printed adapter by Air Mech on that forum and it now prevents the actuator over extending going forward.
All home effort so minimal costs.