Hmm, my C70 is a coupe, but many coupes and convertibles have a mechanism (mirco switches I think is what they are called mainly) that drops the windows as you open/close the doors/roof. The micro switches IIRC assit in correct operation of the windows and the hood, ensuring that the windows move at the right time, each stage of the hood as it goes up and down is done in the correct stages etc. (usually if any of these fail, hoods can get stuck during operation and also windows may fail to operate accordingly.) Does your drivers door window have the same issue, or does it lower and raise slightly to ensure sufficient clearance? I would guess you probably have a faulty mircoswitch or a similar niggle causing the window not to drop. If its a microswitch, many mechanics will fail to realise this and waste time on the main parts that work the soft top. May be worth trying an auto electrician.