Automotive car wash soap is fine. On the plastic windows, never wipe them off dry if you can avoid it. Outside, rinse the window to remove dust and grit, inside gently brush the windows with a soft rag. Always wipe in the same direction, up down or left right, never circular so as to avoids swirls that reflect light. On the canvas, use a brush and car wash soap and rinse well. There are a couple of purpose made top dressings...I have never used any and my top is 14 years old, but it is garage parked.