System for fitting an extension to a glass pane in a motor vehicle, assembly with a system, and method for fitting an extension to a glass pane in a motor vehicle

The system has profile element (4) with extruded profile portion (5) made of plastics material. The profile element has fastening section (6) which is provided for fastening profile element on vehicle pane (20). The receiving portion has latching recess (8) for non-positive and/or positive-locking reception of connecting element. The latching recess comprises soft elastically deformable return element (9) which is arranged such that return element during assembly of connecting element engages over barbs (3) to form a form-fitting receiving portion (10) for barbs. An independent claim is included for method for mounting attachment to vehicle pane.