I always use the original Alfa Romeo convertible window protective cover on mine. A little more time to use it, but I feel it helps save the back window. Doesn't offer the extra support a rolled up towel would provide. I may have to try that. A word of warning though, make sure the window and towel is clean and free of any grit, otherwise you may wind up scratching your window and not protecting it.I owned a '64 Spider and never thought about the back window wear, etc. Recently bought a '90 Spider and as I was about to leave with my purchase, the PO handed me a bath towel and demonstrated how he always placed the rolled-up towel across the back window as he folded it, telling me that this would keep the back window crease-free and later crack-free. Made sense to me as the window on the original top was extremely clear and blemish-free. Anybody else do this?