This is from the fantastic website of Dmitriy Eremeev, a quad. The site also contains several videos. He would appreciate contributions.

Link: http://www.eremeevd.ru/en/podtv_d.htm

Disclaimer: I posted these photos because I think they are great. I am not getting any money from this. If one of these photos belongs to you and you don't want it on the site, just email me (paradevo@yahoo.com) and I'll take it down immediately. I've included links to the sites where I found each image.