Yeah, the cowl does look perfect, until you look at it with the hood closed.
I was thinking just thread the pigtail with the connector right through some gap, and leave the wire hanging out in the well, below the wipers. Then fish it out and make the connection when needed. If it needs to be restrained, maybe a little magnet taped to it, that holds it to something like a screw or another magnet, whatever.
Another idea was to go way up to the right - in the corner of the windshield by the driver's side. The cowl wraps up and around that spot, and there's a kind of rubber lip so it's not quite as simple to poke a clean hole.