I'm having a bit of a problem trying to replace the front windows on my 2008 Swift charisma. The front windows are bowed, so I am replacing them. I ordered all 3 windows from a Polyplastic dealer. The problem is with the centre window, the new window is slightly curved along the top hinge part, this makes it very hard to fit to the existing part of the hinge on the caravan, also the window will not seal properly along the top. The old window is completely straight. The supplier had sent me 2 windows, both are curved and they say according to the manufacturer this is the right window for my caravan. I'm sure I could get over these problems with new/different seals but I don't want to do any damage to the caravan or the new window. Can anyone advise me.