I'll put my .02 in here. I had a Audi A8L and it had not only aluminum body, but also frame (and many models have had since 1994). It was a big "heavy" 4 door sedan and I have had travels through all weather (snow/salt) conditions and neither paint nor metal ever showed signs of degradation. My point being Audi is used all over the world in many harsher environments then we have here in the lower 48...
I'm still wiating for the jury to return about the TV weight vs Trailer component. I do love the extra "planted" feeling of the F450
