Can't cope with mother's decisions

[brookby]

Hi all, I have found this board so insightful recently and would really appreciate some feedback on my current situation.
My dad has undiagnosed dementia - undiagnosed because my mum is scared he will lose his driving license so won't get him help. Well, someone reported him to the dvla, the gp did a report and now he has lost his license on account of his heart which is a separate long term condition, good in my opinion.
The problem is that she won't accept any of this and is becoming more erratic in her denial. I feel like I am expected to help her as the dutiful daughter but I disagree with everything that she says or does and she won't listen to reason (Dad is still driving btw, they are on holiday right now so I can't take the keys away - I have told my aunt who is with them and she is stepping in to stop Mum - Dad isn't even lucid enough to understand in my opinion, Mum is pulling all the strings).
Mum always has to be right, even when everyone is telling her that she is wrong. She complains to me about how hard it is and how depressed she is but won't do anything to help herself, won't accept advice and is now even knowingly breaking the law to suit herself but making excuses (as she doesn't drive).
I'm torn between leaving her to deal with her own mess as she won't listen anyway and the guilt of abandoning her when she most needs help. Do I leave her to sink on her own or just bang my head against the wall and hope she will eventually listen (which is destroying me)? I have a teen with MH issues who is under CAMHS to look after right now so I my capacity is already limited.

Your mum ( sorry but cognitively is she ok do you think?) is putting him and others in danger and it would ultimately end up with your Dad being in the wrong and not her. And yes tell her she might be risking her home if god forbid they had an accident and had to pay damages By hook or by crook get those keys!
And then take a step back , sorry about your predicament, I really understand the stress ,

The second paragraph is very helpful and I will be using it, thank you this is the sort of advice that I was looking for as well as some of the other suggestions of how to handle my Mum.

I navigated a similar situation with DPs and had a stand up row with them after DFs licence was revoked and DF wouldn't hand over the keys for me to sell the car. I set them up with an account with a local taxi firm as well. I eventually got the keys from him but they both sulked for ages afterwards. Would do it again in a heartbeat as he'd lost his spatial awareness with his dementia and kept getting lost and DM couldn't see road signs well enough to navigate!

Motability cars aren't free. The Motability scheme is an expensive way of buying a leasehold vehicle. Many people struggle to lease a car through the Motability scheme as the money comes out of their disability benefits

Report to Motobility they will take it back off of them

I had a similar problem. I was petrified they would have an accident and kill or paralyse someone. Fortunately, they saw my point of view and the car was sold. If they hadn’t, I think I would’ve made a report to the local police. They might come out and speak to them - worst case scenario, they wait for them to go out in the car and pull them - that could result in the police taking the car and having it crushed as they were driving without a licence or insurance. Sounds drastic but I couldn’t live with myself if they put a child or their mummy/daddy in a wheelchair for life. If they did injure someone, there is a fund whereby victims of uninsured drivers are paid compensation-which could run into hundreds of thousands depending on the injury. The insurance companies would then absolutely go after your parents assets (home, saving etc..,) and leave them penniless - is your mother prepared for that??? Brace yourself and exercise some tough love (I know how hard that is). You have to be the grown up here.