My 92 daily driver here in Dallas, with 157,000 miles had the same problem with the same molding. I tried all the products listed in the various posts that provided little help.
Before ordering a new molding myself, as a last ditch effort, I used 0000 steel wool on it and after it takes off that oxidized layer it now looks almost brand new. Nice feature of that steel wool that it will not scratch your glass at all.
I would not use anything more course than the 0000 steel wool, you can find it at any HomeDepot or Lowe's
Good luck