Inside or outside? If you're talking about the inside it should either be patterned cloth or leather.
Yep. Fiberglass. And that textured surface makes it a dust magnet and tough to keep clean. There are a couple of products out there that help. Griots has some good stuff, or when mine was looking grey and faded Mothers Back To Black worked great.
The best and longest lasting treatment fot the thop that I have found is Meguiar's Boat/RV products. I started with the Color Restorer, then the Boat Polish and finally the wax. Removing the years of oxidation and "Vinyl" treatment grease took a long time.