Yea them vents suck, you lose more gas on the road and thats getting to be like $5 a trip now!!
Mine are now relocated above the rub rail and leak no more! ;D
Here is a link to Seaboard, same as Starboard and is what I used, was like 1/3 cheaper the Starboard, and I bought it in 96 X 54 sheets and cut as I needed.
I don't know there shipping info, but you can also see if there is a dealer in your area?? Ask them when you call for info, might be worth it.
Comes in more colors and a non slip texture also!!
http://www.jfreeman.com/cpg_seaboard.html