PIP enhanced version on DLA but standard on PIP. Not eligible for Motability

Hello, I was wondering if anyone else had had similar experiences with the PIP assessments and could offer advice.

My partner has no arms (they have short stumps at the shoulder) and only one leg and has been like this since birth.On the DLA scheme, my partner was eligible for enhanced motability & living support indefinitely.

The DLA awarded them with the enhanced support which allowed them to have a motability car. This is a lifesaver as without it my partner couldn't work, socialise or get around at all.

In their PIP assessment they were only awarded 8 points - as they can walk 20 metres but no more than 50 metres. They need 12 to quality for the enhanced support and the motability car and so now they're looking like they wont have this (although we will appeal!)

In the paper and face to face assessment, we told them that without the car they would not be able to work. Public transport is not an option as they can not but tickets or operate the machines that you put them through, and when on a train/bus the seats are so narrow that they often can't fit their prosthetic leg in the small area. Standing is not an option as they have no hands to hold on to a rail and can't put weight evenly over their 'good' and prosthetic leg - meaning it's unsafe. Walking is also highly problematic as because of the lack of surface area they are often sweaty and over heat from the effort of moving. All the effort is done by their one 'good' leg and they often get sores underneath the artificial leg they wear.

For the living support they qualified for the enhanced support (although in the section where it asks if you can cook and prepare a meal for yourself my partner only scored 4 out of 8 - despite not being able to cook anything, or even get a glass of water from the tap! I don't see how that score has been calculated).

I'm actually staggered that someone who only has only limb and can't do much for themselves wouldn't be eligible for the enhanced support. It's really upsetting to hear that their only lifeline, their car, could be taken away from them. They have extensive adaptions on it in order to drive and the DWP are effectively taking away their ability to work and making him housebound.

My two questions are
-  has anyone been in this situation (around their car and also the level of disability) and had it overturned?

- My partner did qualify for the enhanced living support but didn't score highly in some areas that he can't do (the cooking a meal section as above.) Has anyone experienced this and do you think we should challenge it so his score is higher (i'm thinking for future assessments its best to show the areas he can't do so it's on his record) or leave it as he has qualified for the higher level of support.

Thanks in advance.