Re: Best way to clean vinyl seats?
Soap and water are the best way. For heavy staining, I always use and recommend Clorox Clean-up. It's only 1% bleach and about 6% other cleaners, so bleach damage isn't an issue. My seats are 10 years old and look almost new. Stay away from anything with abrasives in it (Mr. Clean Magic Pads, Ajax, Soft Scrub with pumice, etc). This removes the vinyl's protective layer and allows moisture and dirt to get in below the surface and then the mildew starts from the back side.
When washing the boat, don't forget to wash the seats. Sweat and suntan lotion are absolute killers on vinyls.