I am a Spina Bifida Paraplegic, but on top of that I took a stroke and seizure in January of last year and was left unable to drive or transfer in and out of the car. I thought I was left with the only option of a wav, which I did not want, until a salesman pointed out that I could go for a in-car person hoist, which could be fitted to most non electric cars,
I ordered it with my new Motability car which cost me an extra £600, but if I had wanted the hoist fitted to any other car, it would cost £2,000.
For me it was the preferred d option and remembering that sadly your mother’s condition is only going to get worse, it might be an option worth looking at, if you can afford it, instead of a WAV or a swivel seat which might not work out well in the long tern.
The hoist works well apart from trouble with the cheap and tacky remote control. You do not need to use the remote control. The hoist builds up in three or four parts and can be kept in the boot when not in use.