Can't tighten the wingnuts on oval cross bars tight enough.  Wingnuts are too wide to clear the area for tightening.  Not really tall enough for inside a 2017 Pacifica van.  Came crashing down when one dog laid against the bottom on one side and the other dog was nudging the top on the other.  One dog trapped under it while another one trapped with his legs now in the bars on top of him driving down I-95 and no where to pull off quickly and safely.  Broken clips for crossbars and can't push oval bars back into the clips.  Now, that wouldn't be a problem if there was clearance for the wingnuts and they could be easily undone and retightened, but to get them tight we had to use pliers in the first place. Pushing a loose bar into the clip easily breaks the clip. So things that were supposed to stay separate did not stay separate. Untangling dogs on the side of a highway and not having them escape was not easy.  Suggest improving the wing nut situation with something that can be done easily fingertight or with a small tool.  Check out the wingnut tightening on a Yakima racks for ideas of how to make that work better. They understand how to anchor crossbars to prevent any slippage and provide the ability to reposition if needed. Current suction-cup looking plastic ends do not grip a headliner well on a van (since they are now fabric coated cardboard.  Need something more rubber like (soft/pliable) to prevent slippage against that material.  If you have an older style headliner that has some foam backing, it can bite into that and hold well.  This might work well for some people and in some cars, it was a disaster for me and in the new Pacifica van.