I bought mine from go westy. You have to get the gutter brackets that
mount to the pop top. They have them. They seam to be a tough item to
find. Any store that sells yakama can get them for you but how long it
will take is another story.
  when you mount the brackets keep them as far back on the top as you
can. Otherwise it get difficult to raise the top with the boats on the
rack. I have to struggle with a creek boat and a play boat on top. Any
more than that you better be a weight lifter in the olympics.
   After you install the rack you will have to go to lowes or home depot
to get one of those aluminum platforms with the folding legs (about
$40.00) to get up there to tie the boats on. Works great.