Garage Floor Vent Before Stucco
Here is the proper way to flash a garage floor
vent. As you noticed the vent sits on top of the weep screed metal.
That means that the garage floor vent is sitting on top of the weep screed or overlapping, so the water will run over the week screed and off the buildings safely.
Notice the paper on the sides of the garage vent, the vent sits on top of the paper flashing. This is on the sides only.
Last but not least the top flashing paper goes over the garage floor vent completely.
One more thing I would recommend in a situation like this is to use a nice polyethylene sealant or silicone as an added measure to prevent water damage in the future. Apply the sealant around the garage vent, where it meets the paper and the week screed.