PET sheet window clip

My dog keeps banging on the door windows when he's outside so I put PET sheets over them to avoid having the window break. I wanted to make sure I could easily pull the sheets off for cleaning, so these clips are angled inwards and have a decent friction fit. I did also put some liquid vinyl on the sheet corners to help them stay in place.

These are the sheets I used:
https://www.amazon.com/gp/product/B099S4RR6N