I had our route all planned out to get through Istanbul. We would take the tunnel, the entrance to which was only a couple of kms from where Max had been parked. And we set off at about 10:10am, when we figured "rush hour" (if there is a such a thing in Istanbul) might be over.
We got to the turn off to the tunnel and I saw the height restriction sign that said maximum 2.8 meters. Well, Max is 2.8 meters! I hadn't even thought there might be a height restriction, but apparently this tunnel isn't used by heavy trucks.