I was curious so did a Google.
What are Sacco planks?
This is a Mercedes W124 with so-called 'Sacco Bretter', the plastic side protection strips that run all the way along the car. They are named after their designer, Bruno Sacco, who first applied them on the W126 S-class in 1979
This is a Mercedes W124 with so-called 'Sacco Bretter', the plastic side protection strips that run all the way along the car. They are named after their designer, Bruno Sacco, who first applied them on the W126 S-class in 1979