The surface of the heater pad during installation

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2006 Volvo S80, 2005 Volvo S80, 2004 Volvo S80, 2003 Volvo S80, and 2002 Volvo S80. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Bubbles And Kinks In Pad

Courtesy of VOLVO CARS OF NORTH AMERICA.

CAUTION:

There must not be any bubbles or kinks when the heater pad is bonded to the foam filling.

Bubbles and kinks increase the risk of damage to the pad during use
NOTE:
This applies to the entire surface, but to the heating wires in particular.