Where is the power-lumbar switch on a 2008 Lincoln Town Car?

There isn't a separate "power lumbar" switch on a 2008 Lincoln Town Car. The lumbar support adjustment is typically integrated into the power seat controls. You'll find the controls on the side of the seat cushion itself, usually on the outboard (outside) side. Look for buttons or a dial that allows for adjustment of the lumbar support. If you have power seats, the lumbar adjustment will be part of that system.