Bindi I have a silver gu with 2 light bars mounted under my roofrack and have no issues, if you mount it on top the rack you will more then likely have issues as I initially did untill I moved them under the rack and moved the rack back slightly and have no reflections now . You may however be blinded if you have a white fibreglass antenna on your bull bar but that's a simple fix of using some black heat shrink or paint.