Jin, this is an extremely ingenious solution as I was initially wondering why you would go to the extra trouble of getting a cruise control button when an on-off toggle would do. I then saw the photo and realized that yes, most people will have an extra outlet to the side of their car allowing you to have an OEM look. I'm definitely going to be borrowing this idea when I hard wire my unit in. Did you think this up on your own or did you read it from somewhere else?
Sadly I have but one thanks to give. A++++