I have found it difficult to clean the back window on my SC430. The head rests are close to the glass. I once put the top down 1/2 way, and that made it much easier to reach the whole glass, but has anyone else found and easier way.
(I like to keep the glass clean so as to watch the slower BMW's in my rear view mirror :>]

 

T L - I raised the Hard Top until it was exactly Vertical, and found that this was by far the easiest way to reach the Inside Surfaces of the Rear View Window, without fear that the Top would slowly collapse shut on it's own.

Works like a charm!