I'd use both approaches, if applicable... If the person does not realize they are dangerous behind the wheel, but the conversation might be painful, why not disable the car... as long as it's not an obvious sabotage (in this case he might assume they died from lack of use), why not....

If somehow the person drove and killed someone *despite* the touchy-feely talk, you'd feel pretty stupid... I like the 2 prong approach. Plus uber account...

Both Mom and Dad were on the bubble a couple years ago. Dad with diabetes and some dementia lost his ability to judge space and anything not directly in front of him was not accounted for. Got into 2 fender benders and the DMV stepped in. Mom would drive to the store when she ran out of wine. She still has her license but I told her it was suspended like Dad. Dad was going to drive no matter what. No insurance, no license, he didn't care. I started by parking the Jeep in their garage (they in Santa Barbara and me in San Diego), locked up and disabled (battery). I couldn't sell the Jeep as that would have started a war. I endured 1 year of threats of Dad getting it re-keyed and how he was no longer a free man. He refused taxi service...just being stubborn, and would call friends & neighbors at 2 AM to get a ride to the grocery store. Things improved after the next big step, moved them to assisted living here in SD area. He still talks about his Jeep which is still parked in SB. Rough times.

I hope that in 25-30 years when my keys are taken away the driver less car thing will be a viable option.

Thank you all for the inputs. I've followed the threads discussing this topic with interest as my in-laws are now on the cusp of going to assisted living, but are not quite there. Another day or two and MIL will be moved out of the hospital to a place with critical care nursing which also has assisted living available too. We're hopeful my FIL will see the light and agree to move there. It was heart breaking the other night when he broke down realizing that his wife would probably never be returning to their home to live anymore.
The last few weeks have been more than stressful.

I think the proper way is to start the conversation B4 its an emergency so both parties have an agreeable plan.
Just remember, - this can be you someday.......Hard to grasp that for us young folks.....but old age happens.

I am going through this right now with my mother in law she is 99.
She has never driven but has an electric buggy which she gets stuck with, turns it over and has nearly hit other people including kids.
The local supermarket has banned her from riding in the store.
I cannot get her to understand what the problem is.
Cheers
Bill

Heart-wrenching.

I was visiting my Dad for about a week. He broke his hip and is in assisted care at the time. His dog was just diagnosed with inoperable cancer (8 year old dachshund). Just a whole lot to deal with for him.

I stayed at his house, which my loving brother maintains for him. It is just perfect, the way he and my Mom made it. It was very difficult to be in his house, the way he and my Mom liked it without them there. Everything was in its place and perfect, but the people were missing. It is hard to even write about.