Rainforest, glad to hear it's working so far - hopefully you're onto something and it will keep being a godsend!!

Gigi, does your visor have a mirror in it, or could you stick one on there and then pay attention to Bilby as you're driving, without having to turn around or mess with your rear-view mirror? DD is the same, loves DH and I looking at her and talking to her while we're driving, and our car has mirrors (with a little slidey cover thing) on the visors so that, at the very least, I have the security of knowing I can just glance up and see what she's up to, without taking my eyes completely off the road (it's very handy because she's figured out how to get her arms out of her harness and reach down beside her seat to get toys etc she's dropped - scares the daylights out of me). Maybe if you can make eye contact with Bilby while you're travelling, she might feel better and not put it on for you?
Good luck