In reply to JonC:
I've used a couple of well placed bungees in the past , personally I prefer urban surfing ( on the roof whilst somebody else drives ) , I'd love to do it on the roof of a high speed train one day .
On the back of a pick up stood upright surf style is hell of craic , at least until the vehicle spins out on a bend then into a ditch , thank heavens I was very very drunk .
And remember kids its not big & its not clever !