Any recommendations for devices sold for car transfer?

I think I will give the trash bag a try (and no, it doesn't sound bad). She doesn't go out often so I didn't want to invest in an appliance if it wasn't going to work. Thanks to all of you for your help. It's nice to come up with a creative solution :)

Sounds bad, but a trash bag works for sliding my mother onto the seat. I was told to try that by a therapist.

Go to the internet and google "auto transfer aids". Lot of really interesting items.

any slippery satin or silk handy, like a scarf?