fglaustin, you have definitely checked the front grilles and above the undertray area for a cord? Ours was never used so it was tucked out of the way behind the bumper. The lead is short compared to our other vehicles so it's a bit difficult to plug in/off.

 

did research last night; email with the company that makes zerostart; ford dot com has the same part number for the duratec and the PFI engine,
thus the zerostart 3100002 (which is listed for the duratec) is the same for the PFI engine.
I saw the 3/4 inch pipe plug in the top half of the engine; location is LR (left rear - rear of the transverse engine is closest to the firewall).
had to get my head up close to the brake master cyclinder.
found this youtube video of someone in manitoba (i think) that installed one in the 2.5 engine.

 

Very nice, and helpful. Thank you! I like the way that heater is set up with its power cord, too. And it's 400 watts. Powerful enough to make a difference but less than half a hairdryer, so you won't be pulling a lot of amps. through an extension cord. Good price, too.