The feet of the dishwasher can be removed for installation to lower the opening requirement. Our opening was only 34 3/8 and I believe the installer was able to lower the dishwasher to 34 1/8 for installation. He was able to mount installation brackets on the side, instead of the top to save room as well.
I would call their installation department to confirm the exact spacing before ordering. We were told that none of the European brands (Bosch, Miele, etc.) have the capability of being lowered from 34.5"