Mirror for car seats...no headrest

Does anyone have a solution? Dd is in the middle seat and there isn't a headrest for that position. I can't move her to the outside seats because I have 2 older sons who 1. Want the window. 2. It's easier for them to get in and out and 3. There's too much trouble if they sit next to each other.

How can I set up a mirror to see her? Especially when I am alone with her (otherwise I aske one of the boys to tell me how she is)

Re: Mirror for car seats...no headrest

We got one and had to roll a towel to prop it up, then tie it to the latch. The problem is it blocks a portion of the rear window, so I don't necessarily recommend it. If you look at mirrors on amazon, many people discuss this situation in the comments.