i can't reach the seat belt - inconvenient

My mom just got a used 07 mustang but when I test drove it for the first time I noticed a really inconvenient problem. I can't reach the seat belt without turning around.

My 03 mustang has a black plastic loop that keeps the belt right on the top of the seat and my brother just got an 09 that seemed to have a plastic tether that seemed to push the belt forward. I wonder if this is something I can buy and what's it actually called.

Thanks

Reaching under definitely works plus I didn't notice the seatbelt retainer since it was not attached.

Thank you both.