My car's factory coil has a built-in igniter (4-wire plug, e.g. Opel Corsa B X16XE). Can I use an MSD Ford coil pack?

The MSD coil pack has no internal igniter, so it needs a driver. We normally reuse the igniter from the old coil if it can be separated. If the igniter is not detachable, you need an external coil driver such as the AEM 3-channel coil driver (30-2843). You may also need new spark plug wires if yours don't fit the MSD coil.