Hi All, Been using these ever since I started all year round summer and winter .And to be honest I don't know wether its me not having a good cleaning motion or something wrong with the blades.When I put a new blade in its great, no little lines on window and don't have to do extra detailing. I store the blade in the car and o.k sometimes it might rest on something bending the rubber but recently I have taken it out and lay it flat below the windscreen in the car just to make sure its flat and still after a short while I get a kink in the rubber near the middle.I then use the opposite side and quite often this works for a short time before the same happens again. The bucket on the belt I use is the unger ninja one. I store all my rubbers in the box they come in. Has anyone else come across this problem as its a pain in the back side.How long do your rubbers last in general before you change them.