I keep looking for a setup with a built in intermittent speed, that works with the stock linkages in my 48 Ford F1. I found one about a year ago, but since lost the link. Around here we get misty rain where regular low speed drives you nuts with squeeks from too dry glass, but enough moisture to where you have to flip the switch every 5-10 seconds. My wifes old Toyota 4x4 doesn't have the intermittent switch, and she somehow seems to pick the days when that is exactly what you want and need, to borrow my car!