Mine arrived late last week.
Having seen the posts about tight clearances between the strap edges and the barbell clip I checked, and they were a little tight. However, I also noted that the barbell clip wobbled around within the leather loop, so I just held the barbell clip in one hand and pulled the leather strap with the other and the clearance opened up nicely as the loop elongated slightly. I was then able the install the straps easily by sliding one end of the barbell clip into the receiver through the gap between the two ends of the receiver, then snapping the other end of the barbell into the other side of the receiver.
I suspect that a little gentle tension on the straps will cause the leather loop around the barbell clip to "take a set" over time, so left it installed and filled up my trunk underneath the strap with some cushions and my rolled-up car cover. I'll leave it this way for a couple of weeks and then check to see if the slight elongation of the loop becomes permanent. (It probably will. . .)