Unfortunately you can't buy less then 7 meters unless you visit a yard. BMW part number is 61120142318
. You can easily cut it, you may need more part like 61136901847 and 61136901846 basically many but all part you can find in the link I made to the first part number above.
650i F12 - HUD, 6WA, SLI, Logic 7, Dynamic and Adaptive Drive, Comfort Access, Soft-close, top-view,
Previous X5 40d M Sports and 535d LCI