once installed the Buick branded Thule crossbars have 32-33" wide (across the roof) of usable top space. The ends are covered by the mounting brackets and are slightly wider. There are suggested points to attach the crossbars at but you can mount them just about anywhere front to back along the roof rails.can anyone tell me how wide ( front to back) the cross bars are on any of the options here? I need to attach my much loved ( and used) old cargo box and if too wide- won’t fit. I’m worried the GM and Thule aero bars may be too wide, and the option from Mick’s garage too low ( though I don’t have sunroof, the cargo box connecting mechanism requires a certain amount of clearance).
thanks ( 2018 TourX that I just got brand new for a sweet price )