On ‘18-22 Q3’s the racks were changed on the Q5 to make the job a bit easier with no shortening of the rear rack necessary. The rear q5 racks fit the front of the q3 by sliding the mounts slightly by loosening the adj bolts on top. The rear bar adjustment holes for sliding the mounts further out need to relocated about 5/8” outward on both sides. By drilling the holes and elongating them to join the existing holes, this allows the mounts to slide outward enough to fit properly. And as described in the U.K. article, 2 of the 3 tabs need to be cut/ground off of one side to fit the indentations. Took about 1 hour to complete.