BMW X3 2018–2021 — technical service bulletin
Bulletin B540421 · NHTSA communication 10205090 · issued Nov 1, 2021
Technical service bulletin
communication type
Structure
component
2018–2021
model years
16
vehicle entries
Official summary
This situation can result in 2 customer complaints: 1. Wind noise, and 2. Excess water entry.
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.