Actually I've just realised that the BSH photo only shows you the side of the plate that's exposed when fitted. The channel I refer to is on the "hidden side" when the plate is fitted. I would post a pic but I'm too lazy to go find and take a pic of the stage 1 plate.
As a by the way on this topic, unlike the US, EU engines are able to run in the lean burn "stratified" mode and this partially alleviates the fuel dilution of the oil problem that can increase the risk of pre ignition. As a consequence, the amount of oil that the PCV system can deposits on the valves is decreased (vs a car from the US that only can use homogenous mode).
