WARNING: This page is about a different car, the 2004 Volvo S40, 2003 Volvo S40, 2002 Volvo S40, 2001 Volvo S40, and 2000 Volvo S40. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
For vehicles with inflatable curtains, if the roof needs to be cut open, avoid cutting the gas tubes (placed between the arrows) for the inflatable curtain system.
Fig 1: Placement Of The Inflatable Curtains -- S40 (-04) (2001-2004)