First the seat. The cover is from Walmart $20.00 and helps on long rides but my butt still got sore. See the bump? This is the secret ...under there is a inner tube from the front wheel of a riding lawnmower. Blown up very little (less than 5 lbs). Now I am riding on air. I tried folding a bicycle tube and holding the thing together with duct tape but the low air pressure just moved the air down to the part of the tube I was not sitting on. The simple round inner tube was the answer. Cost $7.00 Harbor Freight.
The black stuff on the tank is the rubber material you put in your tool drawer...available at Lowes $7.00 a roll. It has a post it note kind of stickey back so you can move it around or take it off if you later don't like it. This idea came from the new Suzuki Strom which has some kind of black rubber or something on the tank. My tank was scratched under there and I am too lazy to paint it.
The rest of the roll went in my Pontiac Vibe, in the rear where there are rubber strips which are suppose to keep groceries from moving, but don't... I cut strips of this out put it between the rubber strips...problem solved.