Are you sure you want to mount a 2500mm? Thats seriously long. The vast majority of us use the 2000mm and it will cover everything aft of the front fenders. The factory roof bars aren't as long as many aftermarket racks, so your mounting points will be closer together which may cause instability with an awning that long.
I’m sure I want a 2500. Now do I want it on a stock rack. Not sure.
Might just get a 2000 until I decide what I want to do about a rack
On a stock roof crossbars.