so my last seat foam did not work! so i got this new stuff, HYDRO TURF! from Casseroller Tyler. its used for jet skis
i cut it to the right size, and applied contact cement to the seat and the cushion. after it dried, i stuck the two together and clamped them down.
a day later its PERFECT. its not super cushy, but you can buy different thicknesses, softness, colors, and textures.
get weird with your clamping, make sure all the corners and edges are pressed down.