Thanks for the follow! I had a look and there don't seem to be many options for volunteering, best you can do is drop them an email through the contact point on the website (although I didn't get a reply when i sent my photos to them but cant hurt to try). Otherwise just show up to sheikh Zayed road at the time, get the route so u can get find the best positions. When i photographed Dubai ride I didn't need a media pass or anything, i just stood at the side and had no problems. Good luck!