Hit it with 80 grit to knock it down, then 150 to smooth abit. Then get some Gator guard Truck bed liner ( tintable )You can tint it with the same color of the car. Shoot 3-4 coats,covers a multitude of sins and gives the textured finish of a spray-in bed liner, Been doin this for years and most guys can't figure out how I did it and comment on how nice the texture looks.