I am looking at the Skybox 16 or 18. I have a 2002 Subaru Forester. Which is best between the two? I don't want it to impede the trunk door because I need to get to the dogs. In terms of aerodynamics and overhang I know the 16 will fit the roof line the best, but I would also like the added cargo room of the 18. Anyone have a Skybox 18 on a Forester? Was there to much overhang? Was there a lot of noise when it was moved forward to allow for the trunk to open?