I had a 2012 until I traded it in on a 2020 earlier this year. It was gloss black so I would not have noticed the stains you see. Can you get them off?Less then a year ago.
It almost seems as if the rubber weather-proof molding around all the external mechanical components is deteriorating and the residue is washing down when it rains.
Thanks for the reply.I have the same thing on my white 300.
It is from a diseased tree which I park under that has a fungus. it gets in everywhere and is hard to get off if is sets too long.
If it was "my" tree, I would take a chainsaw too it