yes the lines keep the tarp on the poles, two on each pole is a little more secure, I got the idea from the vanagon.com site when I had my westfalia vanagon
http://vanagon.com/info/accessories/ine ... index.html
i don't use the pole in the gutter
its easier with with two people but takes about 5 to 10 minutes:
clip to van put poles in put your lines on each pole and adjust
i am going to be camping next week at willow springs (vintage motorcycle races) might have to improvise for lack of dirt i'll let you know how it turns out.