I have non-electric side mirrors. I can't for the life of me see how I can adjust these from inside the cab! At the moment I have two positions - folded in and folded out (which I have to do manually). If I want to adjust the mirrors when the are folded out I have to open the windows and use my finger to push the glass. Surely there must be a way of adjusting them properly. There are no obvious knobs on the door or pillar. Please help before I go mad.