Based on previous knowledge, I am aware that certain cars have some features factory-installed, but not enabled unless the specific option is bought. Has anyone verified if the heated seats are wired in the non-heated seat version? The switches are located under the panel near the shift-gear ****.

 

Not sure if this is what you're asking about, but I got dealer installed leather seats which have 'after market' seat heater. There is a button on the bottom side of the seat (in front of the controls to adjust the seat). It works, although it's somewhat harder to find the button and there's no auto off setting. If the button is in the on position, when the car is turned on, you'll get heat. I believe factory installed seat heaters reset to off when the car is turned off.

 

The only feature I'm aware of that is that case is the "alarm" system on the Prius. In that case that is a "software" feature (besides the optional glass breakage sensor).

Sometimes there will be things like wiring in the harness for an option, or a bracket will be in place, but I really doubt that something like a seat heater would be installed but not "enabled". Doesn't make cost/manufacturing sense.

Sorry I can't check though. My car came with the heaters.

 

The OEM installed heated seat control is an alternate-action latching push button. Therefore, it will retain it's last position.