I have a Schumacher SE-1-12S unit hard wired in my car. I have the older model, 1st photo. 2nd photo is the new model, but has the same number SE-1-12S.
I have it placed in the well under the battery and unless your looking for it, it's sort of hidden out of view. The plug I hide behind the armacord when I'm not using it.
When I add items to my car, I try and make them easy to use, and if possible, hidden from view, so as to keep my car original looking....sort of.
Cheers,
Roger