I haven't had this problem with the 2006 GV (yet
), but I do have a few friends who are precision machinists and they have given me a tip to help with polishing plastics and metals to a high shine.
If you are in the US there is a brand of polish you may be able to purchase from any car-care maintenance store (like Checker or Napa Auto Parts) to polish aluminum.
Mother's Mag and Aluminum Polish.
I know what you're thinking, "Aluminum! I mentioned that I had a problem with Plastic pal!"
However, this has consistently worked on several plastic parts (according to the machinists) that require high optical clarity (e.g. - plexiglas panels, led light guides and machined plastic viewing pockets for a hermetic package, etc.). The polish you are using may be too fine to buff out the scratches, whereas this substance may have a slightly more coarse texture.
Legally speaking, I should mention that I do NOT recommend that you use this on anything valuable, but I suggest you test it on a piece of old plastic to restore it as a test. If it works (which it probably will) you must decide yourself if you feel courageous enough to use it on other areas.
P.S. - One of the Machinists demonstrated this on a plastic light cover (on his old 1980s Mustang) and it restored the finish to what appeared to be new. It truly is something you will have to test (on a worthless sample piece of worn/old plastic) and see to believe. Take care.