(Sorry if this is a duplicate post, my computer crashed right after I pressed submit the first time)

Does anyone out there use Yakima Rail-riders with their P5? They're designed to fit in the rails of factory racks. I'm thinking of getting a pair, but would like to know how well they fit the P5 first. Also, which model do you use? There's a model 1, 2, and 3, and little explanation of the difference.

Thanks