There are some pics of the linkages in these threads.Mystery solved. Thank you. I guess it hooks up to some type of linkage to actuate both wipers. There's a hole oriented the same way on the left side of the firewall for right hand drive cars. I've never had to replace one of these on any car that I've owned, some of them more than 20 years old. Might be a different story if I lived in, say, Seattle.