Yes, the Thule WingBar Evo roof rack mounts to fixed points on the roof or your 2018 Infiniti QX30. In addition to the 47" Silver WingBar Evo Crossbars # TH711200 that you referenced you also need the Podium foot Pack # TH460R and the Fit Kit # THKIT3117. You can upgrade the roof rack so it locks with the kit # TH450400.
I have attached some cutouts from the written instructions for the fit kit that you can reference. I you let me know what you will be using the roof rack for I can make... view full answer...