Mine are like this: https://www.amazon.com/XBRN-Headrest-Backseat-Universal-Accessories/dp/B091KJYNQ6/ref=sr_1_48?crid=286FAQFCJ1OE3&keywords=car+hooks+for+headrest&qid=1666379669&qu=eyJxc2MiOiI1LjI0IiwicXNhIjoiNS4wNCIsInFzcCI6IjQuODcifQ%3D%3D&sprefix=car+hook%2Caps%2C200&sr=8-48

My 64oz hangs nicely there when it is filled with no issues.