Fascinating story! There are only a few footpaths which would come out onto the A30 (London Road) and I can't think of one near Devenish Road. Also, there are only a few pubs nearby, I will have a think about where that could have happened. The obvious one would be in Sunningdale and he was walking towards Devenish Road, towards Bagshot, ie towards the oncoming car, if it was coming from Bagshot. Does that make sense!!?
Zoar is the name of a house on Devenish Road. It is now a bright pink cottage / bungalow which is due to be demolished in a rather controversial planning decision! I have a friend who has old photos of Sunningdale and have asked him if he has a nicer, older one, otherwise, I will take one and get it to you ... somehow! It may have had a large garden at one time, but most of the land around it has been developed now.
I have narrowed down the search to one church in Sunningdale and have left a message for the vicar to call me back. All the others did not have any record of his burial or death. I'll keep you posted.