^ That's more tape than is needed, and won't work anyway because of the shape of the bumper.
The bumper is curved and the plate is straight, so the plate won't sit flush against the bumper unless you bend it, which might look weird. If you look in my garage, my plate is in a plastic carrier and is not pressed up against the bumper from end to end. Only the middle portion is actually contacting the bumper and that's where I placed a rectangle of tape. It's worked out well so far.