Broke antenna

I broke the antenna on my 2010 Prius. I'll likely buy a shark fin antenna, but in the meantime should I put some black tape over the stump to prevent water entry? Or, put some black plasti-dip on the stump? The radio reception seems fine.

I'm still not sure how it broke. All I can think of is that when I placed the garage door opener onto the front seat that it started to close the door. I heard a noise, drove back forward - door was fully up which would happen if it encountered an obstacle. Not a mark on the garage door.

Thanks for any advice.