was just about to post the same question NJ. I'm thinking about mounting the button just below the rear wiper control knob. If I can, I'll run the wire right down into the crack. As far as the heating unit, thinking about snipping the side tabs on the bracket, bending the top tabs at 90 degrees and mounting it on the L-bracket the goes around the top of the washer reservoir (where the hood bumper/support is also attached. Unless there's a better idea, I figure it should be enough out of the way..
Other question: which hose do we attach the heater to? The left or the right (the ones to the right of the washer reservoir)?