Actually, the ridged groove was designed so as to avoid dirt stuck in the glass. In other words, it will clearly sighted from behind under heavy weather (rain, snow, storm, fog) and other extreme weather pitfalls. Another MB breakthrough since 1970s.
I'm far from a wiseguy but you will lose the soul of MB if you do this.[
]
I'm far from a wiseguy but you will lose the soul of MB if you do this.[