Autocar Glass Plate B2981
Don't know where the Lea Francis is in that picture but you've got a Swift in the foreground, Bullnose Morris to the right, Amilcar following up behind, a Rover 8 parked on the left verge and a Gordon England Austin seven just visible behind the Swift.
Lea-Francis is the third car in the line, number 234. The car has already appeared in a previous photo.
The Swift driven by L W Fillmore and the Amilcar by K J M Graham.
The competitors passing through Harcombe village en route to the test hill.