Based on a couple of other posts I am planning to pre-wire for my amplifier and sub in my 940 wagon to the drivers rear above the well with the power antenna when I install the new stereo this weekend. Can you see any reason I should not use the power antenna lead as my turn on lead for the amplifier (I will be using line-level inputs which rarely work for automatically waking up the amp)?

My car does have the switch on the dash for the antenna but as I read the schematic, all it does is interrupt the power to the "ant up" lead if it is in the off position. My assumption is that if the car is on (anything but KPI) and the radio is on, the radio head unit is sending power to the antenna assembly unless the antenna switch is in the off position.

I will be in wiring hell all weekend as I also plan to run a USB jack, 3.5mm jack and a new power point into the storage bin of the center arm rest plus route on of the usb plugs into the pocket under the stereo.

Finally, plan to fix the seat heaters one way or another. The stupid "overheat protection" relays are the issue as I have confirmed 12V from the output of the switches and no 12V after the relays. Thinking of direct wiring around the relays...any issues?