I feel like a retard... I still dont understand.... If anything Ill go to 4wheelparts and see if they can help me... I have a buddy who has a hard top on a TJ and his tonno *bestop* just snapps in place... he doesnt have any type of rear windshield channel....maybe I'm just tonno illeterate
The reason your friend doesn't have one is because if you bought a hard top you don't get one. Although, you still need one, or else the cover will just flap in the wind over the tailgate. If water collects on the top it could end up inside as the weight will pull the cover inwards. This is also what keeps your soft top rear window sealed. Otherwise, it will get sucked inward and allow air and water to enter.
Did you look at the link I posted? That's Bestops Instructions with pictures. It doesn't quite show the tailgare retainer in full but it shows how it attaches.
This guide shows the retainer better then the other one:
http://www.bestop.com/installation_guides/79122.pdfNote step #7 shows the brackets that hold the retainer in place on either side of the tailgate opening. #19 and #20 show how it attaches.
Oh and just so you know, the word you're thinking of is 'tonneau'. Although Bestop calls them 'Duster' Deck Covers.