I went to Besttop's web site for installation instructions, and I think I recall something about it, to the tune of mild soap (dish soap) and warm water. use a soft bristle brush to avoid scratching the windows.
I use simple green and a dish brush on the vynal, and a clean soft towel with water for the windows. You can buy a solvent (novus) to remove scratches from [www.4wd.com] not sure where else you can get it though. Hope this helps.