Hello -- planning for the winter projects and one item was to replace the ignition switch. For a 91/S4 it seems like vendors are selling either 3-wire or 4-wire versions (in fact mrfiat sells both versions as suitable for a 91). Looking at the service manual from back in the day, it looks like it should be a 4-wire. Just wondering if anyone had replaced theirs and would know. If not, I'll just hold off ordering until I pull the old one out -- which according to previous alfabb posts will either be a piece of cake or a nightmare.....