Its a very English car but not so the background, the year is 1947, driver a winner of the Australian Grand Prix…
Many thanks to contributor Stephen Dalton for correctly identifying the car and driver as Lex Davison and Bentley 4.5 litre s/c as the car, a big conveyance for that hill despite its open, fast flowing nature!
Lex entered the Bentley in the 12th Rob Roy Hillclimb in 1947. This picturesque venue, in the outer east of Melbourne in the Christmas Hills is still in use by the MG Car Club.
The stretch of main road which goes past Rob Roy’s location off Clintons Road a regular stretch for ‘early morning runs’ by car and bike enthusiasts heading into the Yarra Valley where drivers roads, wineries and fine food are plentiful.
primotipo... 
Maybe I should exclude myself, but I’ll give it a crack anyway.
April 1947 Lex Davison ran his Bentley at Rob Roy Hillclimb #12
Thanks Stephen, yerd’ be correct. Don’t know much about this car, Lex owned so many over the years. Do you know what became of it, supercharged 4.5’s would have been fairly thin on the ground in Oz? Mark