I think I found an easy "fix" for the bulky luggage/roof rack on the Buick. While this doesn't address all of the other issues that have been pointed out concerning this model, I experimented to see what would happen if I highlighted the existing ridges on the roof of the Buick with a silver Sharpie.
I think under normal layout viewing conditions this might be acceptable. I could not justify putting a lot of effort into fabricating a rack out of wire that probably wouldn't look any better when viewed from above. And, as you can see from the photo below, the rack on the Atlas Fairmont still looks much better.
Now all we need to do is convince Round 2 Models to ditch the injection molded rack and pad print one instead. Of course if the molds could be modified to eliminate the three round holes in the roof that would be even better.