Not quite sure I follow--do you just want to add the rails that run from front to back without the cross bars that go side to side? In 2011 Chrysler designed the roof rack rails to "store" the cross bars so that you don't get any wind noise. It's truly ingenious, I think. But if your looking to add a rack without drilling or messing with your headliner etc... You can get a Thule, Yakima etc... I did the Thule since I already have all the Thule accessories from our past 4 vehicles. Here is a write up I did for people about the Thule set up. Best thing about the Thule rack is, when your done with the van you can sell it here, ebay, craiglist or adapt it to your next vehicle which is what we have done for our past vehicles versus paying top dollar for a factory one that will add zero value to your van when you go to sell it. At the end of the day it cost me $310. If you have any questions I'd be glad to answer them.
Thule Guide line