If you drive off the end of the Hogs back from Farnham towards Guildford you join the A3 from the left. Not far along there is a right hand bend. That's where Hawthorn crashed. There is a housing estate there now. A little further on down the hill was Stag Hill Motors, but I believe its gone now.
Coombes' garage was the other side of Guildford on the road to Cranliegh.
PS. Please switch your caps off.