Welcome to the forum Guti.
What engine is in Your van ?
Many years ago I drove a van I think may have been a twin to that one. A Olson Curbmaster.
I was running a CB radio, mounted a 102” whip antenna to the top mirror bracket.
The first trestle bridge I came to, running about 80 MPH, a very loud Kerbang, and then several milder bangity bang bang noises until I got out from under that bridge, scared the out of Me.
Welp, You know that little round ball at the tip of them antennas ? It was no longer there. There was a weird kind of a kink in the end of that unit and I do believe that the little ball at the tip is still probably orbiting the earth.