After building this go kart there are some things that I would have different if I had the material. I would have made the rear axle solid all the way across so it would be stronger. I would have designed the pedal location better, we didn't think about pedals when doing the steering components. Future upgrades include a bigger engine with a clutch and maybe a transmission so we can shift it. I turned out pretty good for being hand built from whatever we could find. We tested it by jumping on it and dropping it and it seems pretty strong. After everything was completed I painted it all black.