I got VW ski/snowboard rack to mount on my existing VW base rack. Ski rack is shorter than the base rack. Therefore I have a couple of questions. Should I center it or can I secure it closer to driver's side? Should I fill open space in base rack profile with a piece of rubber that I had to take off in order to slide in ski rack? I'm afraid that precipitations can do a bad job. I already noticed that black paint from base rack mountings came off in some spots.