The rear wiper on mine was chattering the other day according to the wife (her car), and I was considering doing the E70 replacement. But before doing anything I looked at the arm as it was. Parked the blade vertical by switching off ignition during a wipe. Looked at the arm and it was slightly twisted. After a quick re-alignment (used 2 12" metric crescent wrenches) so the blade was perpendicular to the glass, there's no more chatter and the arm wipes fine.

Around here there is zero chance a rear wiper delete would work - wet, dirty roads in winter (we get warm snaps called Chinooks (look it up Leonardo)) just pile the brown crap on the back glass and no amount of glass treatment would stop it. Wipers Ho!