windshield wiper arms comaptibility? I am trying to locate a set of wiper arms, both driver side and passenger side for my 1968 Buick Electra. I found some on e-bay but I also saw some for a 1975 Eldorado and the pictures look the same for both cars. Does anyone know if the parts are interchangeable? PS Accidently posted in the wrong place the first try. My apologies.