Raggtopp cleaner and sealant.
 

Because of this web site I ordered the RAGGTOPP products to seal the top as well as the horse hair brush to scrub it. I watched the video and he masked off the windows and covered the car with tarps. My local trim shop says masking is not needed. Is it really needed? He says it just washes off once done. The fabric no longer beads water and that's why I'm doing it.

The Raggtopp product is paraffin wax and naphtha. If you get on the glass and paint you will spend a long time getting it off. Why would you think that it would stay on the canvas for months and wipe off the glass/paint?

Excellent point! I will mask it.