After reading the wattages carefully, I decided not to get these and burn out my wires.
Instead, I went with the Xenon bulbs from BMWXENON.COM. They are brighter than the stock Philps bulbs. Not only that, but they give the car a nice HID look. They have a blue tint and really light up the road at night.
You can really see the blue tint through the high beam lights with the lights off. I went with the full set - low/high/fog.
If you order them be sure to request that the fog light model that you need for your 2001 Z3 is the H7, not the H1.