Pulling Cutting Wire Into Car:

WARNING: This page is about a different car, the 2003 BMW X5, 2002 BMW X5, 2001 BMW X5, and 2000 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.

Push wire starter (2) from inside at a suitable point through adhesive bead
Feed wire end (1) into hole of wire starter (2) and bend back
Pull in both wires in succession crossways

NOTE: Crossing the wire cuts through the adhesive bead completely.

Fig 1: Pushing Wire Starter From Inside At A Suitable Point Through Adhesive Bead

Courtesy of BMW OF NORTH AMERICA, INC.