I havent started mine yet.. but I have the tub liner kit ready to go for re surfacing my Hardtop. you can apply it with a gun for a smother less textured look or you can use the roller in the kit and apply it this way for a rougher more textured look.
Im just too lazy to take the top off and do the prep work atm though..
I bought rustoleum tub liner from REPCO for $100 on special..
https://images-na.ssl-images-amazon....L._SL1050_.jpg