Yes, but to be honest I have never tried to install one over a factory rack.[/QUOTE]
Mine was installed over part of the stock roof rack; I took the side rails off and left the center ribs on. There is about an inch of clearance from the top of the ribs to the bottom of the rack. This rack's totally awesome it is so versatile with the way they've engineered all the available holddowns and such, well worth the price. HTH.