Dealer installed mine. But last year I replaced the external vent cap. And after removing the old cap and looking thru the hole, I could see thru the hole that the dryer vent hose was routed in a "cavity" area behind the rear panel of the washer/dryer prep cabinet and the front cap. I assume the dealer removed the rear panel of the cabinet to drill the hole thru the side, or at least to locate the hole between frame members. Hole did come out right in the curve of the moulding. Luck or careful planning? Don't know of any other way they could have accessed it to route the hose back there though.
I agree that those instructions do not seem to make a lot of sense. This pic of mine seems to be the typical location for dryer vents with front washer/dryer cabinets.
Edit: this pic shows right side up on my PC, but upside down on my iPhone. Have no idea why.
