I bought some a year or two ago and tried to do some parts.. it's a LOT harder than it looks. They make it look so easy on Youtube, but in my experiences, it has always come out messed up in one way or another.
The thing about doing quad palstics is that it'll scratch up easily in the harsh environments that a quad goes through unless you clearcoat it. Then of course if you don't use quality clearcoat or have it done professionaly, the clear will start to flake/peel off too eventually, and it will look like crap.