different metal to different metal contact, corrosion multiplies.
I had a car with chrome window surrounds and stainless steel bumpers,,
The bumpers were top class. cut down any errant pedestrian nps..never corroded,
The chrome stuff, heavy corrosion where the trim clipped on to the door edges.
a possible soln.rust treat ,prime and paint the chrome strip attachment areas and the metal chrome strips themselves.
Wrap the strips in "chrome vinyl" from
Amount needed shouldnt cost you more than £10.
With proper preparation and reasonable care in application, should last the life of the car.
If window surround strips are rubber from new this wouldnt work..too much flex..
There is also aluminium tape, but there s no room for even a tiny stretching error with that.It also oxidises like crazy.
It looks like chrome when applied initially, but unless its covered or cleaned every few days it just goes dull..like brass