Should we help dad buy a car?

Dad (my 80 year old FIL) was in a car accident that totaled his car. He was not found at fault for the accident. The other driver was ticketed.

Although the accident was not his fault, he is without a car right now and we think this is a good time to discuss his driving abilities. We have been concerned about his driving for a while now & slowly, for over a year we have been talking with him about some of our concerns.

Overall he has safe driving habits. No road rage, uses turn signals & understands rules of the road. But he is a very slow driver. He thinks everyone around him is going fast even when they are going the speed limit. His perception of what is going on around him seems to be off & his reaction time seems slow. Despite his overall safe habits this one area really frightens us because we are afraid that he may not react fast enough to changing circumstances on the road.

We understand that this is a difficult privelge for one to lose. We have tried to help prepare him with caring but firm conversations, but it is very hard to get him to acknowledge his decline & the reality of this situation & to begin looking for alternatives.

We don't think he will be open to relinquishing his keys. What if he decides he will buy another car despite our urging him not too? He doesn't have much money to work with. He is prone to go out & purchase a clunker.

My husband feels like that is also an unsafe alternative. He feels like if his dad is determined to keep driving it's his responsibility to help him find the safest car possible.

What do you think? Is that endangering & enabling him or providing a sense of safety he might not otherwise have if he bought a car on his own?

Thanks for your help!