To use these in a +12V auto application, you'll want to use the 22 volt parts because the standoff voltage is actually lower than the rated voltage. The 16 volt part has a standoff voltage of around 13.5 volts and that's too low. The 22 volt part has a standoff voltage of about 18.5 volts and is just about right. Connect the banded end to +12V at the distributor and the other to ground. I'd put a couple in parallel to increase the power rating just in case you have a really noisey regulator.
