A shame there wasn't some kind of secondary circuit so that if the fuse blows so that you can't operate the windows from the normal switches, when the roof is activated there is a seperatly fused circuit to operate the windows.
I say this beacuse:
On my old 1990 BMW, you could operate the windows, ignition off, door open (wish MB did this).
A fault developed on my drivers window switch which meant it was arcing a bit when used and it kept popping the fuse. Until I could get to the dealer to buy a new one, I discovered that with the normal fuse blown, you got a 2nd chance by opening the door, as the window convenience feature ran from a different fuse.