Hand wash only, air dry...

Years ago I worked in the car wash biz and the deal was any stock items were the responsibility of the car wash. Aftermarket things like lights and bed covers were at your own risk. In this case the wash should have taken off the antenna.

I remember my favorite part of the day was cleaning up at the end of the day. I'd come out with my hands full of license plate frames, lens covers and bent up metal molding strips (this was in the 1980s :))